/* sort - sort lines of text (with all kinds of options). Copyright (C) 1988-2020 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Written December 1988 by Mike Haertel. The author may be reached (Email) at the address mike@gnu.ai.mit.edu, or (US mail) as Mike Haertel c/o Free Software Foundation. Ørn E. Hansen added NLS support in 1997. */ #include #include #include #include #include #include #include #include #include "system.h" #include "argmatch.h" #include "die.h" #include "error.h" #include "fadvise.h" #include "filevercmp.h" #include "flexmember.h" #include "hard-locale.h" #include "hash.h" #include "heap.h" #include "ignore-value.h" #include "md5.h" #include "mbswidth.h" #include "nproc.h" #include "physmem.h" #include "posixver.h" #include "quote.h" #include "randread.h" #include "readtokens0.h" #include "stdlib--.h" #include "strnumcmp.h" #include "xmemcoll.h" #include "xnanosleep.h" #include "xstrtol.h" #include "xstrtol-error.h" #ifndef RLIMIT_DATA struct rlimit { size_t rlim_cur; }; # define getrlimit(Resource, Rlp) (-1) #endif /* The official name of this program (e.g., no 'g' prefix). */ #define PROGRAM_NAME "sort" #define AUTHORS \ proper_name ("Mike Haertel"), \ proper_name ("Paul Eggert") #if HAVE_LANGINFO_CODESET # include #endif /* Use SA_NOCLDSTOP as a proxy for whether the sigaction machinery is present. */ #ifndef SA_NOCLDSTOP # define SA_NOCLDSTOP 0 /* No sigprocmask. Always 'return' zero. */ # define sigprocmask(How, Set, Oset) (0) # define sigset_t int # if ! HAVE_SIGINTERRUPT # define siginterrupt(sig, flag) /* empty */ # endif #endif #if !defined OPEN_MAX && defined NR_OPEN # define OPEN_MAX NR_OPEN #endif #if !defined OPEN_MAX # define OPEN_MAX 20 #endif #define UCHAR_LIM (UCHAR_MAX + 1) #ifndef DEFAULT_TMPDIR # define DEFAULT_TMPDIR "/tmp" #endif /* Maximum number of lines to merge every time a NODE is taken from the merge queue. Node is at LEVEL in the binary merge tree, and is responsible for merging TOTAL lines. */ #define MAX_MERGE(total, level) (((total) >> (2 * ((level) + 1))) + 1) /* Heuristic value for the number of lines for which it is worth creating a subthread, during an internal merge sort. I.e., it is a small number of "average" lines for which sorting via two threads is faster than sorting via one on an "average" system. On a dual-core 2.0 GHz i686 system with 3GB of RAM and 2MB of L2 cache, a file containing 128K lines of gensort -a output is sorted slightly faster with --parallel=2 than with --parallel=1. By contrast, using --parallel=1 is about 10% faster than using --parallel=2 with a 64K-line input. */ enum { SUBTHREAD_LINES_HEURISTIC = 128 * 1024 }; verify (4 <= SUBTHREAD_LINES_HEURISTIC); /* The number of threads after which there are diminishing performance gains. */ enum { DEFAULT_MAX_THREADS = 8 }; /* Exit statuses. */ enum { /* POSIX says to exit with status 1 if invoked with -c and the input is not properly sorted. */ SORT_OUT_OF_ORDER = 1, /* POSIX says any other irregular exit must exit with a status code greater than 1. */ SORT_FAILURE = 2 }; enum { /* The number of times we should try to fork a compression process (we retry if the fork call fails). We don't _need_ to compress temp files, this is just to reduce disk access, so this number can be small. Each retry doubles in duration. */ MAX_FORK_TRIES_COMPRESS = 4, /* The number of times we should try to fork a decompression process. If we can't fork a decompression process, we can't sort, so this number should be big. Each retry doubles in duration. */ MAX_FORK_TRIES_DECOMPRESS = 9 }; enum { /* Level of the end-of-merge node, one level above the root. */ MERGE_END = 0, /* Level of the root node in merge tree. */ MERGE_ROOT = 1 }; /* The representation of the decimal point in the current locale. */ static int decimal_point; /* Thousands separator; if -1, then there isn't one. */ static int thousands_sep; /* Nonzero if the corresponding locales are hard. */ static bool hard_LC_COLLATE; #if HAVE_NL_LANGINFO static bool hard_LC_TIME; #endif #define NONZERO(x) ((x) != 0) /* The kind of blanks for '-b' to skip in various options. */ enum blanktype { bl_start, bl_end, bl_both }; /* The character marking end of line. Default to \n. */ static char eolchar = '\n'; /* Lines are held in core as counted strings. */ struct line { char *text; /* Text of the line. */ size_t length; /* Length including final newline. */ char *keybeg; /* Start of first key. */ char *keylim; /* Limit of first key. */ }; /* Input buffers. */ struct buffer { char *buf; /* Dynamically allocated buffer, partitioned into 3 regions: - input data; - unused area; - an array of lines, in reverse order. */ size_t used; /* Number of bytes used for input data. */ size_t nlines; /* Number of lines in the line array. */ size_t alloc; /* Number of bytes allocated. */ size_t left; /* Number of bytes left from previous reads. */ size_t line_bytes; /* Number of bytes to reserve for each line. */ bool eof; /* An EOF has been read. */ }; /* Sort key. */ struct keyfield { size_t sword; /* Zero-origin 'word' to start at. */ size_t schar; /* Additional characters to skip. */ size_t eword; /* Zero-origin last 'word' of key. */ size_t echar; /* Additional characters in field. */ bool const *ignore; /* Boolean array of characters to ignore. */ char const *translate; /* Translation applied to characters. */ bool skipsblanks; /* Skip leading blanks when finding start. */ bool skipeblanks; /* Skip leading blanks when finding end. */ bool numeric; /* Flag for numeric comparison. Handle strings of digits with optional decimal point, but no exponential notation. */ bool random; /* Sort by random hash of key. */ bool general_numeric; /* Flag for general, numeric comparison. Handle numbers in exponential notation. */ bool human_numeric; /* Flag for sorting by human readable units with either SI or IEC prefixes. */ bool month; /* Flag for comparison by month name. */ bool reverse; /* Reverse the sense of comparison. */ bool version; /* sort by version number */ bool traditional_used; /* Traditional key option format is used. */ struct keyfield *next; /* Next keyfield to try. */ }; struct month { char const *name; int val; }; /* Binary merge tree node. */ struct merge_node { struct line *lo; /* Lines to merge from LO child node. */ struct line *hi; /* Lines to merge from HI child node. */ struct line *end_lo; /* End of available lines from LO. */ struct line *end_hi; /* End of available lines from HI. */ struct line **dest; /* Pointer to destination of merge. */ size_t nlo; /* Total Lines remaining from LO. */ size_t nhi; /* Total lines remaining from HI. */ struct merge_node *parent; /* Parent node. */ struct merge_node *lo_child; /* LO child node. */ struct merge_node *hi_child; /* HI child node. */ unsigned int level; /* Level in merge tree. */ bool queued; /* Node is already in heap. */ pthread_mutex_t lock; /* Lock for node operations. */ }; /* Priority queue of merge nodes. */ struct merge_node_queue { struct heap *priority_queue; /* Priority queue of merge tree nodes. */ pthread_mutex_t mutex; /* Lock for queue operations. */ pthread_cond_t cond; /* Conditional wait for empty queue to populate when popping. */ }; /* Used to implement --unique (-u). */ static struct line saved_line; /* FIXME: None of these tables work with multibyte character sets. Also, there are many other bugs when handling multibyte characters. One way to fix this is to rewrite 'sort' to use wide characters internally, but doing this with good performance is a bit tricky. */ /* Table of blanks. */ static bool blanks[UCHAR_LIM]; /* Table of non-printing characters. */ static bool nonprinting[UCHAR_LIM]; /* Table of non-dictionary characters (not letters, digits, or blanks). */ static bool nondictionary[UCHAR_LIM]; /* Translation table folding lower case to upper. */ static char fold_toupper[UCHAR_LIM]; #define MONTHS_PER_YEAR 12 /* Table mapping month names to integers. Alphabetic order allows binary search. */ static struct month monthtab[] = { {"APR", 4}, {"AUG", 8}, {"DEC", 12}, {"FEB", 2}, {"JAN", 1}, {"JUL", 7}, {"JUN", 6}, {"MAR", 3}, {"MAY", 5}, {"NOV", 11}, {"OCT", 10}, {"SEP", 9} }; /* During the merge phase, the number of files to merge at once. */ #define NMERGE_DEFAULT 16 /* Minimum size for a merge or check buffer. */ #define MIN_MERGE_BUFFER_SIZE (2 + sizeof (struct line)) /* Minimum sort size; the code might not work with smaller sizes. */ #define MIN_SORT_SIZE (nmerge * MIN_MERGE_BUFFER_SIZE) /* The number of bytes needed for a merge or check buffer, which can function relatively efficiently even if it holds only one line. If a longer line is seen, this value is increased. */ static size_t merge_buffer_size = MAX (MIN_MERGE_BUFFER_SIZE, 256 * 1024); /* The approximate maximum number of bytes of main memory to use, as specified by the user. Zero if the user has not specified a size. */ static size_t sort_size; /* The initial allocation factor for non-regular files. This is used, e.g., when reading from a pipe. Don't make it too big, since it is multiplied by ~130 to obtain the size of the actual buffer sort will allocate. Also, there may be 8 threads all doing this at the same time. */ #define INPUT_FILE_SIZE_GUESS (128 * 1024) /* Array of directory names in which any temporary files are to be created. */ static char const **temp_dirs; /* Number of temporary directory names used. */ static size_t temp_dir_count; /* Number of allocated slots in temp_dirs. */ static size_t temp_dir_alloc; /* Flag to reverse the order of all comparisons. */ static bool reverse; /* Flag for stable sort. This turns off the last ditch bytewise comparison of lines, and instead leaves lines in the same order they were read if all keys compare equal. */ static bool stable; /* If TAB has this value, blanks separate fields. */ enum { TAB_DEFAULT = CHAR_MAX + 1 }; /* Tab character separating fields. If TAB_DEFAULT, then fields are separated by the empty string between a non-blank character and a blank character. */ static int tab = TAB_DEFAULT; /* Flag to remove consecutive duplicate lines from the output. Only the last of a sequence of equal lines will be output. */ static bool unique; /* Nonzero if any of the input files are the standard input. */ static bool have_read_stdin; /* List of key field comparisons to be tried. */ static struct keyfield *keylist; /* Program used to (de)compress temp files. Must accept -d. */ static char const *compress_program; /* Annotate the output with extra info to aid the user. */ static bool debug; /* Maximum number of files to merge in one go. If more than this number are present, temp files will be used. */ static unsigned int nmerge = NMERGE_DEFAULT; /* Output an error to stderr and exit using async-signal-safe routines. This can be used safely from signal handlers, and between fork and exec of multithreaded processes. */ static void async_safe_die (int, const char *) ATTRIBUTE_NORETURN; static void async_safe_die (int errnum, const char *errstr) { ignore_value (write (STDERR_FILENO, errstr, strlen (errstr))); /* Even if defined HAVE_STRERROR_R, we can't use it, as it may return a translated string etc. and even if not may call malloc which is unsafe. We might improve this by testing for sys_errlist and using that if available. For now just report the error number. */ if (errnum) { char errbuf[INT_BUFSIZE_BOUND (errnum)]; char *p = inttostr (errnum, errbuf); ignore_value (write (STDERR_FILENO, ": errno ", 8)); ignore_value (write (STDERR_FILENO, p, strlen (p))); } ignore_value (write (STDERR_FILENO, "\n", 1)); _exit (SORT_FAILURE); } /* Report MESSAGE for FILE, then clean up and exit. If FILE is null, it represents standard output. */ static void sort_die (char const *, char const *) ATTRIBUTE_NORETURN; static void sort_die (char const *message, char const *file) { die (SORT_FAILURE, errno, "%s: %s", message, quotef (file ? file : _("standard output"))); } void usage (int status) { if (status != EXIT_SUCCESS) emit_try_help (); else { printf (_("\ Usage: %s [OPTION]... [FILE]...\n\ or: %s [OPTION]... --files0-from=F\n\ "), program_name, program_name); fputs (_("\ Write sorted concatenation of all FILE(s) to standard output.\n\ "), stdout); emit_stdin_note (); emit_mandatory_arg_note (); fputs (_("\ Ordering options:\n\ \n\ "), stdout); fputs (_("\ -b, --ignore-leading-blanks ignore leading blanks\n\ -d, --dictionary-order consider only blanks and alphanumeric characters\ \n\ -f, --ignore-case fold lower case to upper case characters\n\ "), stdout); fputs (_("\ -g, --general-numeric-sort compare according to general numerical value\n\ -i, --ignore-nonprinting consider only printable characters\n\ -M, --month-sort compare (unknown) < 'JAN' < ... < 'DEC'\n\ "), stdout); fputs (_("\ -h, --human-numeric-sort compare human readable numbers (e.g., 2K 1G)\n\ "), stdout); fputs (_("\ -n, --numeric-sort compare according to string numerical value\n\ -R, --random-sort shuffle, but group identical keys. See shuf(1)\n\ --random-source=FILE get random bytes from FILE\n\ -r, --reverse reverse the result of comparisons\n\ "), stdout); fputs (_("\ --sort=WORD sort according to WORD:\n\ general-numeric -g, human-numeric -h, month -M,\ \n\ numeric -n, random -R, version -V\n\ -V, --version-sort natural sort of (version) numbers within text\n\ \n\ "), stdout); fputs (_("\ Other options:\n\ \n\ "), stdout); fputs (_("\ --batch-size=NMERGE merge at most NMERGE inputs at once;\n\ for more use temp files\n\ "), stdout); fputs (_("\ -c, --check, --check=diagnose-first check for sorted input; do not sort\n\ -C, --check=quiet, --check=silent like -c, but do not report first bad line\ \n\ --compress-program=PROG compress temporaries with PROG;\n\ decompress them with PROG -d\n\ "), stdout); fputs (_("\ --debug annotate the part of the line used to sort,\n\ and warn about questionable usage to stderr\n\ --files0-from=F read input from the files specified by\n\ NUL-terminated names in file F;\n\ If F is - then read names from standard input\n\ "), stdout); fputs (_("\ -k, --key=KEYDEF sort via a key; KEYDEF gives location and type\n\ -m, --merge merge already sorted files; do not sort\n\ "), stdout); fputs (_("\ -o, --output=FILE write result to FILE instead of standard output\n\ -s, --stable stabilize sort by disabling last-resort comparison\ \n\ -S, --buffer-size=SIZE use SIZE for main memory buffer\n\ "), stdout); printf (_("\ -t, --field-separator=SEP use SEP instead of non-blank to blank transition\n\ -T, --temporary-directory=DIR use DIR for temporaries, not $TMPDIR or %s;\n\ multiple options specify multiple directories\n\ --parallel=N change the number of sorts run concurrently to N\n\ -u, --unique with -c, check for strict ordering;\n\ without -c, output only the first of an equal run\ \n\ "), DEFAULT_TMPDIR); fputs (_("\ -z, --zero-terminated line delimiter is NUL, not newline\n\ "), stdout); fputs (HELP_OPTION_DESCRIPTION, stdout); fputs (VERSION_OPTION_DESCRIPTION, stdout); fputs (_("\ \n\ KEYDEF is F[.C][OPTS][,F[.C][OPTS]] for start and stop position, where F is a\n\ field number and C a character position in the field; both are origin 1, and\n\ the stop position defaults to the line's end. If neither -t nor -b is in\n\ effect, characters in a field are counted from the beginning of the preceding\n\ whitespace. OPTS is one or more single-letter ordering options [bdfgiMhnRrV],\ \n\ which override global ordering options for that key. If no key is given, use\n\ the entire line as the key. Use --debug to diagnose incorrect key usage.\n\ \n\ SIZE may be followed by the following multiplicative suffixes:\n\ "), stdout); fputs (_("\ % 1% of memory, b 1, K 1024 (default), and so on for M, G, T, P, E, Z, Y.\n\ \n\ *** WARNING ***\n\ The locale specified by the environment affects sort order.\n\ Set LC_ALL=C to get the traditional sort order that uses\n\ native byte values.\n\ "), stdout ); emit_ancillary_info (PROGRAM_NAME); } exit (status); } /* For long options that have no equivalent short option, use a non-character as a pseudo short option, starting with CHAR_MAX + 1. */ enum { CHECK_OPTION = CHAR_MAX + 1, COMPRESS_PROGRAM_OPTION, DEBUG_PROGRAM_OPTION, FILES0_FROM_OPTION, NMERGE_OPTION, RANDOM_SOURCE_OPTION, SORT_OPTION, PARALLEL_OPTION }; static char const short_options[] = "-bcCdfghik:mMno:rRsS:t:T:uVy:z"; static struct option const long_options[] = { {"ignore-leading-blanks", no_argument, NULL, 'b'}, {"check", optional_argument, NULL, CHECK_OPTION}, {"compress-program", required_argument, NULL, COMPRESS_PROGRAM_OPTION}, {"debug", no_argument, NULL, DEBUG_PROGRAM_OPTION}, {"dictionary-order", no_argument, NULL, 'd'}, {"ignore-case", no_argument, NULL, 'f'}, {"files0-from", required_argument, NULL, FILES0_FROM_OPTION}, {"general-numeric-sort", no_argument, NULL, 'g'}, {"ignore-nonprinting", no_argument, NULL, 'i'}, {"key", required_argument, NULL, 'k'}, {"merge", no_argument, NULL, 'm'}, {"month-sort", no_argument, NULL, 'M'}, {"numeric-sort", no_argument, NULL, 'n'}, {"human-numeric-sort", no_argument, NULL, 'h'}, {"version-sort", no_argument, NULL, 'V'}, {"random-sort", no_argument, NULL, 'R'}, {"random-source", required_argument, NULL, RANDOM_SOURCE_OPTION}, {"sort", required_argument, NULL, SORT_OPTION}, {"output", required_argument, NULL, 'o'}, {"reverse", no_argument, NULL, 'r'}, {"stable", no_argument, NULL, 's'}, {"batch-size", required_argument, NULL, NMERGE_OPTION}, {"buffer-size", required_argument, NULL, 'S'}, {"field-separator", required_argument, NULL, 't'}, {"temporary-directory", required_argument, NULL, 'T'}, {"unique", no_argument, NULL, 'u'}, {"zero-terminated", no_argument, NULL, 'z'}, {"parallel", required_argument, NULL, PARALLEL_OPTION}, {GETOPT_HELP_OPTION_DECL}, {GETOPT_VERSION_OPTION_DECL}, {NULL, 0, NULL, 0}, }; #define CHECK_TABLE \ _ct_("quiet", 'C') \ _ct_("silent", 'C') \ _ct_("diagnose-first", 'c') static char const *const check_args[] = { #define _ct_(_s, _c) _s, CHECK_TABLE NULL #undef _ct_ }; static char const check_types[] = { #define _ct_(_s, _c) _c, CHECK_TABLE #undef _ct_ }; #define SORT_TABLE \ _st_("general-numeric", 'g') \ _st_("human-numeric", 'h') \ _st_("month", 'M') \ _st_("numeric", 'n') \ _st_("random", 'R') \ _st_("version", 'V') static char const *const sort_args[] = { #define _st_(_s, _c) _s, SORT_TABLE NULL #undef _st_ }; static char const sort_types[] = { #define _st_(_s, _c) _c, SORT_TABLE #undef _st_ }; /* The set of signals that are caught. */ static sigset_t caught_signals; /* Critical section status. */ struct cs_status { bool valid; sigset_t sigs; }; /* Enter a critical section. */ static void cs_enter (struct cs_status *status) { int ret = pthread_sigmask (SIG_BLOCK, &caught_signals, &status->sigs); status->valid = ret == 0; } /* Leave a critical section. */ static void cs_leave (struct cs_status const *status) { if (status->valid) { /* Ignore failure when restoring the signal mask. */ pthread_sigmask (SIG_SETMASK, &status->sigs, NULL); } } /* Possible states for a temp file. If compressed, the file's status is unreaped or reaped, depending on whether 'sort' has waited for the subprocess to finish. */ enum { UNCOMPRESSED, UNREAPED, REAPED }; /* The list of temporary files. */ struct tempnode { struct tempnode *volatile next; pid_t pid; /* The subprocess PID; undefined if state == UNCOMPRESSED. */ char state; char name[FLEXIBLE_ARRAY_MEMBER]; }; static struct tempnode *volatile temphead; static struct tempnode *volatile *temptail = &temphead; /* A file to be sorted. */ struct sortfile { /* The file's name. */ char const *name; /* Non-null if this is a temporary file, in which case NAME == TEMP->name. */ struct tempnode *temp; }; /* Map PIDs of unreaped subprocesses to their struct tempnode objects. */ static Hash_table *proctab; enum { INIT_PROCTAB_SIZE = 47 }; static size_t proctab_hasher (void const *entry, size_t tabsize) { struct tempnode const *node = entry; return node->pid % tabsize; } static bool proctab_comparator (void const *e1, void const *e2) { struct tempnode const *n1 = e1; struct tempnode const *n2 = e2; return n1->pid == n2->pid; } /* The number of unreaped child processes. */ static pid_t nprocs; static bool delete_proc (pid_t); /* If PID is positive, wait for the child process with that PID to exit, and assume that PID has already been removed from the process table. If PID is 0 or -1, clean up some child that has exited (by waiting for it, and removing it from the proc table) and return the child's process ID. However, if PID is 0 and no children have exited, return 0 without waiting. */ static pid_t reap (pid_t pid) { int status; pid_t cpid = waitpid ((pid ? pid : -1), &status, (pid ? 0 : WNOHANG)); if (cpid < 0) die (SORT_FAILURE, errno, _("waiting for %s [-d]"), quoteaf (compress_program)); else if (0 < cpid && (0 < pid || delete_proc (cpid))) { if (! WIFEXITED (status) || WEXITSTATUS (status)) die (SORT_FAILURE, 0, _("%s [-d] terminated abnormally"), quoteaf (compress_program)); --nprocs; } return cpid; } /* TEMP represents a new process; add it to the process table. Create the process table the first time it's called. */ static void register_proc (struct tempnode *temp) { if (! proctab) { proctab = hash_initialize (INIT_PROCTAB_SIZE, NULL, proctab_hasher, proctab_comparator, NULL); if (! proctab) xalloc_die (); } temp->state = UNREAPED; if (! hash_insert (proctab, temp)) xalloc_die (); } /* If PID is in the process table, remove it and return true. Otherwise, return false. */ static bool delete_proc (pid_t pid) { struct tempnode test; test.pid = pid; struct tempnode *node = hash_delete (proctab, &test); if (! node) return false; node->state = REAPED; return true; } /* Remove PID from the process table, and wait for it to exit if it hasn't already. */ static void wait_proc (pid_t pid) { if (delete_proc (pid)) reap (pid); } /* Reap any exited children. Do not block; reap only those that have already exited. */ static void reap_exited (void) { while (0 < nprocs && reap (0)) continue; } /* Reap at least one exited child, waiting if necessary. */ static void reap_some (void) { reap (-1); reap_exited (); } /* Reap all children, waiting if necessary. */ static void reap_all (void) { while (0 < nprocs) reap (-1); } /* Clean up any remaining temporary files. */ static void cleanup (void) { struct tempnode const *node; for (node = temphead; node; node = node->next) unlink (node->name); temphead = NULL; } /* Cleanup actions to take when exiting. */ static void exit_cleanup (void) { if (temphead) { /* Clean up any remaining temporary files in a critical section so that a signal handler does not try to clean them too. */ struct cs_status cs; cs_enter (&cs); cleanup (); cs_leave (&cs); } close_stdout (); } /* Create a new temporary file, returning its newly allocated tempnode. Store into *PFD the file descriptor open for writing. If the creation fails, return NULL and store -1 into *PFD if the failure is due to file descriptor exhaustion and SURVIVE_FD_EXHAUSTION; otherwise, die. */ static struct tempnode * create_temp_file (int *pfd, bool survive_fd_exhaustion) { static char const slashbase[] = "/sortXXXXXX"; static size_t temp_dir_index; int fd; int saved_errno; char const *temp_dir = temp_dirs[temp_dir_index]; size_t len = strlen (temp_dir); struct tempnode *node = xmalloc (FLEXSIZEOF (struct tempnode, name, len + sizeof slashbase)); char *file = node->name; struct cs_status cs; memcpy (file, temp_dir, len); memcpy (file + len, slashbase, sizeof slashbase); node->next = NULL; if (++temp_dir_index == temp_dir_count) temp_dir_index = 0; /* Create the temporary file in a critical section, to avoid races. */ cs_enter (&cs); fd = mkostemp (file, O_CLOEXEC); if (0 <= fd) { *temptail = node; temptail = &node->next; } saved_errno = errno; cs_leave (&cs); errno = saved_errno; if (fd < 0) { if (! (survive_fd_exhaustion && errno == EMFILE)) die (SORT_FAILURE, errno, _("cannot create temporary file in %s"), quoteaf (temp_dir)); free (node); node = NULL; } *pfd = fd; return node; } /* Return a pointer to stdout status, or NULL on failure. */ static struct stat * get_outstatus (void) { static int outstat_errno; static struct stat outstat; if (outstat_errno == 0) outstat_errno = fstat (STDOUT_FILENO, &outstat) == 0 ? -1 : errno; return outstat_errno < 0 ? &outstat : NULL; } /* Return a stream for FILE, opened with mode HOW. If HOW is "w", the file is already open on standard output, and needs to be truncated unless FILE is null. When opening for input, "-" means standard input. To avoid confusion, do not return file descriptors STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO when opening an ordinary FILE. Return NULL if unsuccessful. Use fadvise to specify an access pattern for input files. There are a few hints we could possibly provide, and after careful testing it was decided that specifying FADVISE_SEQUENTIAL was not detrimental to any cases. On Linux 2.6.31, this option doubles the size of read ahead performed and thus was seen to benefit these cases: Merging Sorting with a smaller internal buffer Reading from faster flash devices In _addition_ one could also specify other hints... FADVISE_WILLNEED was tested, but Linux 2.6.31 at least uses that to _synchronously_ prepopulate the cache with the specified range. While sort does need to read all of its input before outputting, a synchronous read of the whole file up front precludes any processing that sort could do in parallel with the system doing read ahead of the data. This was seen to have negative effects in a couple of cases: Merging Sorting with a smaller internal buffer This option was seen to shorten the runtime for sort on a multicore system with lots of RAM and other processes competing for CPU. It could be argued that more explicit scheduling hints with 'nice' et. al. are more appropriate for this situation. FADVISE_NOREUSE is a possibility as it could lower the priority of input data in the cache as sort will only need to process it once. However its functionality has changed over Linux kernel versions and as of 2.6.31 it does nothing and thus we can't depend on what it might do in future. FADVISE_DONTNEED is not appropriate for user specified input files, but for temp files we do want to drop the cache immediately after processing. This is done implicitly however when the files are unlinked. */ static FILE * stream_open (char const *file, char const *how) { FILE *fp; if (*how == 'r') { if (STREQ (file, "-")) { have_read_stdin = true; fp = stdin; } else { int fd = open (file, O_RDONLY | O_CLOEXEC); fp = fd < 0 ? NULL : fdopen (fd, how); } fadvise (fp, FADVISE_SEQUENTIAL); } else if (*how == 'w') { if (file && ftruncate (STDOUT_FILENO, 0) != 0) { int ftruncate_errno = errno; struct stat *outst = get_outstatus (); if (!outst || S_ISREG (outst->st_mode) || S_TYPEISSHM (outst)) die (SORT_FAILURE, ftruncate_errno, _("%s: error truncating"), quotef (file)); } fp = stdout; } else assert (!"unexpected mode passed to stream_open"); return fp; } /* Same as stream_open, except always return a non-null value; die on failure. */ static FILE * xfopen (char const *file, char const *how) { FILE *fp = stream_open (file, how); if (!fp) sort_die (_("open failed"), file); return fp; } /* Close FP, whose name is FILE, and report any errors. */ static void xfclose (FILE *fp, char const *file) { switch (fileno (fp)) { case STDIN_FILENO: /* Allow reading stdin from tty more than once. */ if (feof (fp)) clearerr (fp); break; case STDOUT_FILENO: /* Don't close stdout just yet. close_stdout does that. */ if (fflush (fp) != 0) sort_die (_("fflush failed"), file); break; default: if (fclose (fp) != 0) sort_die (_("close failed"), file); break; } } /* Move OLDFD to NEWFD. If OLDFD != NEWFD, NEWFD is not close-on-exec. */ static void move_fd (int oldfd, int newfd) { if (oldfd != newfd) { /* This should never fail for our usage. */ dup2 (oldfd, newfd); close (oldfd); } } /* Fork a child process for piping to and do common cleanup. The TRIES parameter specifies how many times to try to fork before giving up. Return the PID of the child, or -1 (setting errno) on failure. */ static pid_t pipe_fork (int pipefds[2], size_t tries) { #if HAVE_WORKING_FORK struct tempnode *saved_temphead; int saved_errno; double wait_retry = 0.25; pid_t pid IF_LINT ( = -1); struct cs_status cs; if (pipe2 (pipefds, O_CLOEXEC) < 0) return -1; /* At least NMERGE + 1 subprocesses are needed. More could be created, but uncontrolled subprocess generation can hurt performance significantly. Allow at most NMERGE + 2 subprocesses, on the theory that there may be some useful parallelism by letting compression for the previous merge finish (1 subprocess) in parallel with the current merge (NMERGE + 1 subprocesses). */ if (nmerge + 1 < nprocs) reap_some (); while (tries--) { /* This is so the child process won't delete our temp files if it receives a signal before exec-ing. */ cs_enter (&cs); saved_temphead = temphead; temphead = NULL; pid = fork (); saved_errno = errno; if (pid) temphead = saved_temphead; cs_leave (&cs); errno = saved_errno; if (0 <= pid || errno != EAGAIN) break; else { xnanosleep (wait_retry); wait_retry *= 2; reap_exited (); } } if (pid < 0) { saved_errno = errno; close (pipefds[0]); close (pipefds[1]); errno = saved_errno; } else if (pid == 0) { close (STDIN_FILENO); close (STDOUT_FILENO); } else ++nprocs; return pid; #else /* ! HAVE_WORKING_FORK */ return -1; #endif } /* Create a temporary file and, if asked for, start a compressor to that file. Set *PFP to the file handle and return the address of the new temp node. If the creation fails, return NULL if the failure is due to file descriptor exhaustion and SURVIVE_FD_EXHAUSTION; otherwise, die. */ static struct tempnode * maybe_create_temp (FILE **pfp, bool survive_fd_exhaustion) { int tempfd; struct tempnode *node = create_temp_file (&tempfd, survive_fd_exhaustion); if (! node) return NULL; node->state = UNCOMPRESSED; if (compress_program) { int pipefds[2]; node->pid = pipe_fork (pipefds, MAX_FORK_TRIES_COMPRESS); if (0 < node->pid) { close (tempfd); close (pipefds[0]); tempfd = pipefds[1]; register_proc (node); } else if (node->pid == 0) { /* Being the child of a multithreaded program before exec, we're restricted to calling async-signal-safe routines here. */ close (pipefds[1]); move_fd (tempfd, STDOUT_FILENO); move_fd (pipefds[0], STDIN_FILENO); execlp (compress_program, compress_program, (char *) NULL); async_safe_die (errno, "couldn't execute compress program"); } } *pfp = fdopen (tempfd, "w"); if (! *pfp) sort_die (_("couldn't create temporary file"), node->name); return node; } /* Create a temporary file and, if asked for, start a compressor to that file. Set *PFP to the file handle and return the address of the new temp node. Die on failure. */ static struct tempnode * create_temp (FILE **pfp) { return maybe_create_temp (pfp, false); } /* Open a compressed temp file and start a decompression process through which to filter the input. Return NULL (setting errno to EMFILE) if we ran out of file descriptors, and die on any other kind of failure. */ static FILE * open_temp (struct tempnode *temp) { int tempfd, pipefds[2]; FILE *fp = NULL; if (temp->state == UNREAPED) wait_proc (temp->pid); tempfd = open (temp->name, O_RDONLY); if (tempfd < 0) return NULL; pid_t child = pipe_fork (pipefds, MAX_FORK_TRIES_DECOMPRESS); switch (child) { case -1: if (errno != EMFILE) die (SORT_FAILURE, errno, _("couldn't create process for %s -d"), quoteaf (compress_program)); close (tempfd); errno = EMFILE; break; case 0: /* Being the child of a multithreaded program before exec, we're restricted to calling async-signal-safe routines here. */ close (pipefds[0]); move_fd (tempfd, STDIN_FILENO); move_fd (pipefds[1], STDOUT_FILENO); execlp (compress_program, compress_program, "-d", (char *) NULL); async_safe_die (errno, "couldn't execute compress program (with -d)"); default: temp->pid = child; register_proc (temp); close (tempfd); close (pipefds[1]); fp = fdopen (pipefds[0], "r"); if (! fp) { int saved_errno = errno; close (pipefds[0]); errno = saved_errno; } break; } return fp; } /* Append DIR to the array of temporary directory names. */ static void add_temp_dir (char const *dir) { if (temp_dir_count == temp_dir_alloc) temp_dirs = X2NREALLOC (temp_dirs, &temp_dir_alloc); temp_dirs[temp_dir_count++] = dir; } /* Remove NAME from the list of temporary files. */ static void zaptemp (char const *name) { struct tempnode *volatile *pnode; struct tempnode *node; struct tempnode *next; int unlink_status; int unlink_errno = 0; struct cs_status cs; for (pnode = &temphead; (node = *pnode)->name != name; pnode = &node->next) continue; if (node->state == UNREAPED) wait_proc (node->pid); /* Unlink the temporary file in a critical section to avoid races. */ next = node->next; cs_enter (&cs); unlink_status = unlink (name); unlink_errno = errno; *pnode = next; cs_leave (&cs); if (unlink_status != 0) error (0, unlink_errno, _("warning: cannot remove: %s"), quotef (name)); if (! next) temptail = pnode; free (node); } #if HAVE_NL_LANGINFO static int struct_month_cmp (void const *m1, void const *m2) { struct month const *month1 = m1; struct month const *month2 = m2; return strcmp (month1->name, month2->name); } #endif /* Initialize the character class tables. */ static void inittables (void) { size_t i; for (i = 0; i < UCHAR_LIM; ++i) { blanks[i] = field_sep (i); nonprinting[i] = ! isprint (i); nondictionary[i] = ! isalnum (i) && ! field_sep (i); fold_toupper[i] = toupper (i); } #if HAVE_NL_LANGINFO /* If we're not in the "C" locale, read different names for months. */ if (hard_LC_TIME) { for (i = 0; i < MONTHS_PER_YEAR; i++) { char const *s; size_t s_len; size_t j, k; char *name; s = nl_langinfo (ABMON_1 + i); s_len = strlen (s); monthtab[i].name = name = xmalloc (s_len + 1); monthtab[i].val = i + 1; for (j = k = 0; j < s_len; j++) if (! isblank (to_uchar (s[j]))) name[k++] = fold_toupper[to_uchar (s[j])]; name[k] = '\0'; } qsort (monthtab, MONTHS_PER_YEAR, sizeof *monthtab, struct_month_cmp); } #endif } /* Specify how many inputs may be merged at once. This may be set on the command-line with the --batch-size option. */ static void specify_nmerge (int oi, char c, char const *s) { uintmax_t n; struct rlimit rlimit; enum strtol_error e = xstrtoumax (s, NULL, 10, &n, ""); /* Try to find out how many file descriptors we'll be able to open. We need at least nmerge + 3 (STDIN_FILENO, STDOUT_FILENO and STDERR_FILENO). */ unsigned int max_nmerge = ((getrlimit (RLIMIT_NOFILE, &rlimit) == 0 ? rlimit.rlim_cur : OPEN_MAX) - 3); if (e == LONGINT_OK) { nmerge = n; if (nmerge != n) e = LONGINT_OVERFLOW; else { if (nmerge < 2) { error (0, 0, _("invalid --%s argument %s"), long_options[oi].name, quote (s)); die (SORT_FAILURE, 0, _("minimum --%s argument is %s"), long_options[oi].name, quote ("2")); } else if (max_nmerge < nmerge) { e = LONGINT_OVERFLOW; } else return; } } if (e == LONGINT_OVERFLOW) { char max_nmerge_buf[INT_BUFSIZE_BOUND (max_nmerge)]; error (0, 0, _("--%s argument %s too large"), long_options[oi].name, quote (s)); die (SORT_FAILURE, 0, _("maximum --%s argument with current rlimit is %s"), long_options[oi].name, uinttostr (max_nmerge, max_nmerge_buf)); } else xstrtol_fatal (e, oi, c, long_options, s); } /* Specify the amount of main memory to use when sorting. */ static void specify_sort_size (int oi, char c, char const *s) { uintmax_t n; char *suffix; enum strtol_error e = xstrtoumax (s, &suffix, 10, &n, "EgGkKmMPtTYZ"); /* The default unit is KiB. */ if (e == LONGINT_OK && ISDIGIT (suffix[-1])) { if (n <= UINTMAX_MAX / 1024) n *= 1024; else e = LONGINT_OVERFLOW; } /* A 'b' suffix means bytes; a '%' suffix means percent of memory. */ if (e == LONGINT_INVALID_SUFFIX_CHAR && ISDIGIT (suffix[-1]) && ! suffix[1]) switch (suffix[0]) { case 'b': e = LONGINT_OK; break; case '%': { double mem = physmem_total () * n / 100; /* Use "<", not "<=", to avoid problems with rounding. */ if (mem < UINTMAX_MAX) { n = mem; e = LONGINT_OK; } else e = LONGINT_OVERFLOW; } break; } if (e == LONGINT_OK) { /* If multiple sort sizes are specified, take the maximum, so that option order does not matter. */ if (n < sort_size) return; sort_size = n; if (sort_size == n) { sort_size = MAX (sort_size, MIN_SORT_SIZE); return; } e = LONGINT_OVERFLOW; } xstrtol_fatal (e, oi, c, long_options, s); } /* Specify the number of threads to spawn during internal sort. */ static size_t specify_nthreads (int oi, char c, char const *s) { uintmax_t nthreads; enum strtol_error e = xstrtoumax (s, NULL, 10, &nthreads, ""); if (e == LONGINT_OVERFLOW) return SIZE_MAX; if (e != LONGINT_OK) xstrtol_fatal (e, oi, c, long_options, s); if (SIZE_MAX < nthreads) nthreads = SIZE_MAX; if (nthreads == 0) die (SORT_FAILURE, 0, _("number in parallel must be nonzero")); return nthreads; } /* Return the default sort size. */ static size_t default_sort_size (void) { /* Let SIZE be MEM, but no more than the maximum object size, total memory, or system resource limits. Don't bother to check for values like RLIM_INFINITY since in practice they are not much less than SIZE_MAX. */ size_t size = SIZE_MAX; struct rlimit rlimit; if (getrlimit (RLIMIT_DATA, &rlimit) == 0 && rlimit.rlim_cur < size) size = rlimit.rlim_cur; #ifdef RLIMIT_AS if (getrlimit (RLIMIT_AS, &rlimit) == 0 && rlimit.rlim_cur < size) size = rlimit.rlim_cur; #endif /* Leave a large safety margin for the above limits, as failure can occur when they are exceeded. */ size /= 2; #ifdef RLIMIT_RSS /* Leave a 1/16 margin for RSS to leave room for code, stack, etc. Exceeding RSS is not fatal, but can be quite slow. */ if (getrlimit (RLIMIT_RSS, &rlimit) == 0 && rlimit.rlim_cur / 16 * 15 < size) size = rlimit.rlim_cur / 16 * 15; #endif /* Let MEM be available memory or 1/8 of total memory, whichever is greater. */ double avail = physmem_available (); double total = physmem_total (); double mem = MAX (avail, total / 8); /* Leave a 1/4 margin for physical memory. */ if (total * 0.75 < size) size = total * 0.75; /* Return the minimum of MEM and SIZE, but no less than MIN_SORT_SIZE. Avoid the MIN macro here, as it is not quite right when only one argument is floating point. */ if (mem < size) size = mem; return MAX (size, MIN_SORT_SIZE); } /* Return the sort buffer size to use with the input files identified by FPS and FILES, which are alternate names of the same files. NFILES gives the number of input files; NFPS may be less. Assume that each input line requires LINE_BYTES extra bytes' worth of line information. Do not exceed the size bound specified by the user (or a default size bound, if the user does not specify one). */ static size_t sort_buffer_size (FILE *const *fps, size_t nfps, char *const *files, size_t nfiles, size_t line_bytes) { /* A bound on the input size. If zero, the bound hasn't been determined yet. */ static size_t size_bound; /* In the worst case, each input byte is a newline. */ size_t worst_case_per_input_byte = line_bytes + 1; /* Keep enough room for one extra input line and an extra byte. This extra room might be needed when preparing to read EOF. */ size_t size = worst_case_per_input_byte + 1; for (size_t i = 0; i < nfiles; i++) { struct stat st; off_t file_size; size_t worst_case; if ((i < nfps ? fstat (fileno (fps[i]), &st) : STREQ (files[i], "-") ? fstat (STDIN_FILENO, &st) : stat (files[i], &st)) != 0) sort_die (_("stat failed"), files[i]); if (S_ISREG (st.st_mode)) file_size = st.st_size; else { /* The file has unknown size. If the user specified a sort buffer size, use that; otherwise, guess the size. */ if (sort_size) return sort_size; file_size = INPUT_FILE_SIZE_GUESS; } if (! size_bound) { size_bound = sort_size; if (! size_bound) size_bound = default_sort_size (); } /* Add the amount of memory needed to represent the worst case where the input consists entirely of newlines followed by a single non-newline. Check for overflow. */ worst_case = file_size * worst_case_per_input_byte + 1; if (file_size != worst_case / worst_case_per_input_byte || size_bound - size <= worst_case) return size_bound; size += worst_case; } return size; } /* Initialize BUF. Reserve LINE_BYTES bytes for each line; LINE_BYTES must be at least sizeof (struct line). Allocate ALLOC bytes initially. */ static void initbuf (struct buffer *buf, size_t line_bytes, size_t alloc) { /* Ensure that the line array is properly aligned. If the desired size cannot be allocated, repeatedly halve it until allocation succeeds. The smaller allocation may hurt overall performance, but that's better than failing. */ while (true) { alloc += sizeof (struct line) - alloc % sizeof (struct line); buf->buf = malloc (alloc); if (buf->buf) break; alloc /= 2; if (alloc <= line_bytes + 1) xalloc_die (); } buf->line_bytes = line_bytes; buf->alloc = alloc; buf->used = buf->left = buf->nlines = 0; buf->eof = false; } /* Return one past the limit of the line array. */ static inline struct line * buffer_linelim (struct buffer const *buf) { void *linelim = buf->buf + buf->alloc; return linelim; } /* Return a pointer to the first character of the field specified by KEY in LINE. */ static char * begfield (struct line const *line, struct keyfield const *key) { char *ptr = line->text, *lim = ptr + line->length - 1; size_t sword = key->sword; size_t schar = key->schar; /* The leading field separator itself is included in a field when -t is absent. */ if (tab != TAB_DEFAULT) while (ptr < lim && sword--) { while (ptr < lim && *ptr != tab) ++ptr; if (ptr < lim) ++ptr; } else while (ptr < lim && sword--) { while (ptr < lim && blanks[to_uchar (*ptr)]) ++ptr; while (ptr < lim && !blanks[to_uchar (*ptr)]) ++ptr; } /* If we're ignoring leading blanks when computing the Start of the field, skip past them here. */ if (key->skipsblanks) while (ptr < lim && blanks[to_uchar (*ptr)]) ++ptr; /* Advance PTR by SCHAR (if possible), but no further than LIM. */ ptr = MIN (lim, ptr + schar); return ptr; } /* Return the limit of (a pointer to the first character after) the field in LINE specified by KEY. */ static char * limfield (struct line const *line, struct keyfield const *key) { char *ptr = line->text, *lim = ptr + line->length - 1; size_t eword = key->eword, echar = key->echar; if (echar == 0) eword++; /* Skip all of end field. */ /* Move PTR past EWORD fields or to one past the last byte on LINE, whichever comes first. If there are more than EWORD fields, leave PTR pointing at the beginning of the field having zero-based index, EWORD. If a delimiter character was specified (via -t), then that 'beginning' is the first character following the delimiting TAB. Otherwise, leave PTR pointing at the first 'blank' character after the preceding field. */ if (tab != TAB_DEFAULT) while (ptr < lim && eword--) { while (ptr < lim && *ptr != tab) ++ptr; if (ptr < lim && (eword || echar)) ++ptr; } else while (ptr < lim && eword--) { while (ptr < lim && blanks[to_uchar (*ptr)]) ++ptr; while (ptr < lim && !blanks[to_uchar (*ptr)]) ++ptr; } #ifdef POSIX_UNSPECIFIED /* The following block of code makes GNU sort incompatible with standard Unix sort, so it's ifdef'd out for now. The POSIX spec isn't clear on how to interpret this. FIXME: request clarification. From: kwzh@gnu.ai.mit.edu (Karl Heuer) Date: Thu, 30 May 96 12:20:41 -0400 [Translated to POSIX 1003.1-2001 terminology by Paul Eggert.] [...]I believe I've found another bug in 'sort'. $ cat /tmp/sort.in a b c 2 d pq rs 1 t $ textutils-1.15/src/sort -k1.7,1.7 skipeblanks) while (ptr < lim && blanks[to_uchar (*ptr)]) ++ptr; /* Advance PTR by ECHAR (if possible), but no further than LIM. */ ptr = MIN (lim, ptr + echar); } return ptr; } /* Fill BUF reading from FP, moving buf->left bytes from the end of buf->buf to the beginning first. If EOF is reached and the file wasn't terminated by a newline, supply one. Set up BUF's line table too. FILE is the name of the file corresponding to FP. Return true if some input was read. */ static bool fillbuf (struct buffer *buf, FILE *fp, char const *file) { struct keyfield const *key = keylist; char eol = eolchar; size_t line_bytes = buf->line_bytes; size_t mergesize = merge_buffer_size - MIN_MERGE_BUFFER_SIZE; if (buf->eof) return false; if (buf->used != buf->left) { memmove (buf->buf, buf->buf + buf->used - buf->left, buf->left); buf->used = buf->left; buf->nlines = 0; } while (true) { char *ptr = buf->buf + buf->used; struct line *linelim = buffer_linelim (buf); struct line *line = linelim - buf->nlines; size_t avail = (char *) linelim - buf->nlines * line_bytes - ptr; char *line_start = buf->nlines ? line->text + line->length : buf->buf; while (line_bytes + 1 < avail) { /* Read as many bytes as possible, but do not read so many bytes that there might not be enough room for the corresponding line array. The worst case is when the rest of the input file consists entirely of newlines, except that the last byte is not a newline. */ size_t readsize = (avail - 1) / (line_bytes + 1); size_t bytes_read = fread (ptr, 1, readsize, fp); char *ptrlim = ptr + bytes_read; char *p; avail -= bytes_read; if (bytes_read != readsize) { if (ferror (fp)) sort_die (_("read failed"), file); if (feof (fp)) { buf->eof = true; if (buf->buf == ptrlim) return false; if (line_start != ptrlim && ptrlim[-1] != eol) *ptrlim++ = eol; } } /* Find and record each line in the just-read input. */ while ((p = memchr (ptr, eol, ptrlim - ptr))) { /* Delimit the line with NUL. This eliminates the need to temporarily replace the last byte with NUL when calling xmemcoll, which increases performance. */ *p = '\0'; ptr = p + 1; line--; line->text = line_start; line->length = ptr - line_start; mergesize = MAX (mergesize, line->length); avail -= line_bytes; if (key) { /* Precompute the position of the first key for efficiency. */ line->keylim = (key->eword == SIZE_MAX ? p : limfield (line, key)); if (key->sword != SIZE_MAX) line->keybeg = begfield (line, key); else { if (key->skipsblanks) while (blanks[to_uchar (*line_start)]) line_start++; line->keybeg = line_start; } } line_start = ptr; } ptr = ptrlim; if (buf->eof) break; } buf->used = ptr - buf->buf; buf->nlines = buffer_linelim (buf) - line; if (buf->nlines != 0) { buf->left = ptr - line_start; merge_buffer_size = mergesize + MIN_MERGE_BUFFER_SIZE; return true; } { /* The current input line is too long to fit in the buffer. Increase the buffer size and try again, keeping it properly aligned. */ size_t line_alloc = buf->alloc / sizeof (struct line); buf->buf = x2nrealloc (buf->buf, &line_alloc, sizeof (struct line)); buf->alloc = line_alloc * sizeof (struct line); } } } /* Table that maps characters to order-of-magnitude values. */ static char const unit_order[UCHAR_LIM] = { #if ! ('K' == 75 && 'M' == 77 && 'G' == 71 && 'T' == 84 && 'P' == 80 \ && 'E' == 69 && 'Z' == 90 && 'Y' == 89 && 'k' == 107) /* This initializer syntax works on all C99 hosts. For now, use it only on non-ASCII hosts, to ease the pain of porting to pre-C99 ASCII hosts. */ ['K']=1, ['M']=2, ['G']=3, ['T']=4, ['P']=5, ['E']=6, ['Z']=7, ['Y']=8, ['k']=1, #else /* Generate the following table with this command: perl -e 'my %a=(k=>1, K=>1, M=>2, G=>3, T=>4, P=>5, E=>6, Z=>7, Y=>8); foreach my $i (0..255) {my $c=chr($i); $a{$c} ||= 0;print "$a{$c}, "}'\ |fmt */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 3, 0, 0, 0, 1, 0, 2, 0, 0, 5, 0, 0, 0, 4, 0, 0, 0, 0, 8, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 #endif }; /* Traverse number given as *number consisting of digits, thousands_sep, and decimal_point chars only. Returns the highest digit found in the number, or '\0' if no digit has been found. Upon return *number points at the character that immediately follows after the given number. */ static unsigned char traverse_raw_number (char const **number) { char const *p = *number; unsigned char ch; unsigned char max_digit = '\0'; bool ends_with_thousands_sep = false; /* Scan to end of number. Decimals or separators not followed by digits stop the scan. Numbers ending in decimals or separators are thus considered to be lacking in units. FIXME: add support for multibyte thousands_sep and decimal_point. */ while (ISDIGIT (ch = *p++)) { if (max_digit < ch) max_digit = ch; /* Allow to skip only one occurrence of thousands_sep to avoid finding the unit in the next column in case thousands_sep matches as blank and is used as column delimiter. */ ends_with_thousands_sep = (*p == thousands_sep); if (ends_with_thousands_sep) ++p; } if (ends_with_thousands_sep) { /* thousands_sep not followed by digit is not allowed. */ *number = p - 2; return max_digit; } if (ch == decimal_point) while (ISDIGIT (ch = *p++)) if (max_digit < ch) max_digit = ch; *number = p - 1; return max_digit; } /* Return an integer that represents the order of magnitude of the unit following the number. The number may contain thousands separators and a decimal point, but it may not contain leading blanks. Negative numbers get negative orders; zero numbers have a zero order. */ static int _GL_ATTRIBUTE_PURE find_unit_order (char const *number) { bool minus_sign = (*number == '-'); char const *p = number + minus_sign; unsigned char max_digit = traverse_raw_number (&p); if ('0' < max_digit) { unsigned char ch = *p; int order = unit_order[ch]; return (minus_sign ? -order : order); } else return 0; } /* Compare numbers A and B ending in units with SI or IEC prefixes < K/k < M < G < T < P < E < Z < Y */ static int human_numcompare (char const *a, char const *b) { while (blanks[to_uchar (*a)]) a++; while (blanks[to_uchar (*b)]) b++; int diff = find_unit_order (a) - find_unit_order (b); return (diff ? diff : strnumcmp (a, b, decimal_point, thousands_sep)); } /* Compare strings A and B as numbers without explicitly converting them to machine numbers. Comparatively slow for short strings, but asymptotically hideously fast. */ static int numcompare (char const *a, char const *b) { while (blanks[to_uchar (*a)]) a++; while (blanks[to_uchar (*b)]) b++; return strnumcmp (a, b, decimal_point, thousands_sep); } /* Work around a problem whereby the long double value returned by glibc's strtold ("NaN", ...) contains uninitialized bits: clear all bytes of A and B before calling strtold. FIXME: remove this function if gnulib guarantees that strtold's result is always well defined. */ static int nan_compare (char const *sa, char const *sb) { long double a; memset (&a, 0, sizeof a); a = strtold (sa, NULL); long double b; memset (&b, 0, sizeof b); b = strtold (sb, NULL); return memcmp (&a, &b, sizeof a); } static int general_numcompare (char const *sa, char const *sb) { /* FIXME: maybe add option to try expensive FP conversion only if A and B can't be compared more cheaply/accurately. */ char *ea; char *eb; long double a = strtold (sa, &ea); long double b = strtold (sb, &eb); /* Put conversion errors at the start of the collating sequence. */ if (sa == ea) return sb == eb ? 0 : -1; if (sb == eb) return 1; /* Sort numbers in the usual way, where -0 == +0. Put NaNs after conversion errors but before numbers; sort them by internal bit-pattern, for lack of a more portable alternative. */ return (a < b ? -1 : a > b ? 1 : a == b ? 0 : b == b ? -1 : a == a ? 1 : nan_compare (sa, sb)); } /* Return an integer in 1..12 of the month name MONTH. Return 0 if the name in S is not recognized. */ static int getmonth (char const *month, char **ea) { size_t lo = 0; size_t hi = MONTHS_PER_YEAR; while (blanks[to_uchar (*month)]) month++; do { size_t ix = (lo + hi) / 2; char const *m = month; char const *n = monthtab[ix].name; for (;; m++, n++) { if (!*n) { if (ea) *ea = (char *) m; return monthtab[ix].val; } if (to_uchar (fold_toupper[to_uchar (*m)]) < to_uchar (*n)) { hi = ix; break; } else if (to_uchar (fold_toupper[to_uchar (*m)]) > to_uchar (*n)) { lo = ix + 1; break; } } } while (lo < hi); return 0; } /* A randomly chosen MD5 state, used for random comparison. */ static struct md5_ctx random_md5_state; /* Initialize the randomly chosen MD5 state. */ static void random_md5_state_init (char const *random_source) { unsigned char buf[MD5_DIGEST_SIZE]; struct randread_source *r = randread_new (random_source, sizeof buf); if (! r) sort_die (_("open failed"), random_source); randread (r, buf, sizeof buf); if (randread_free (r) != 0) sort_die (_("close failed"), random_source); md5_init_ctx (&random_md5_state); md5_process_bytes (buf, sizeof buf, &random_md5_state); } /* This is like strxfrm, except it reports any error and exits. */ static size_t xstrxfrm (char *restrict dest, char const *restrict src, size_t destsize) { errno = 0; size_t translated_size = strxfrm (dest, src, destsize); if (errno) { error (0, errno, _("string transformation failed")); error (0, 0, _("set LC_ALL='C' to work around the problem")); die (SORT_FAILURE, 0, _("the untransformed string was %s"), quotearg_n_style (0, locale_quoting_style, src)); } return translated_size; } /* Compare the keys TEXTA (of length LENA) and TEXTB (of length LENB) using one or more random hash functions. TEXTA[LENA] and TEXTB[LENB] must be zero. */ static int compare_random (char *restrict texta, size_t lena, char *restrict textb, size_t lenb) { /* XFRM_DIFF records the equivalent of memcmp on the transformed data. This is used to break ties if there is a checksum collision, and this is good enough given the astronomically low probability of a collision. */ int xfrm_diff = 0; char stackbuf[4000]; char *buf = stackbuf; size_t bufsize = sizeof stackbuf; void *allocated = NULL; uint32_t dig[2][MD5_DIGEST_SIZE / sizeof (uint32_t)]; struct md5_ctx s[2]; s[0] = s[1] = random_md5_state; if (hard_LC_COLLATE) { char const *lima = texta + lena; char const *limb = textb + lenb; while (true) { /* Transform the text into the basis of comparison, so that byte strings that would otherwise considered to be equal are considered equal here even if their bytes differ. Each time through this loop, transform one null-terminated string's worth from TEXTA or from TEXTB or both. That way, there's no need to store the transformation of the whole line, if it contains many null-terminated strings. */ /* Store the transformed data into a big-enough buffer. */ /* A 3X size guess avoids the overhead of calling strxfrm twice on typical implementations. Don't worry about size_t overflow, as the guess need not be correct. */ size_t guess_bufsize = 3 * (lena + lenb) + 2; if (bufsize < guess_bufsize) { bufsize = MAX (guess_bufsize, bufsize * 3 / 2); free (allocated); buf = allocated = malloc (bufsize); if (! buf) { buf = stackbuf; bufsize = sizeof stackbuf; } } size_t sizea = (texta < lima ? xstrxfrm (buf, texta, bufsize) + 1 : 0); bool a_fits = sizea <= bufsize; size_t sizeb = (textb < limb ? (xstrxfrm ((a_fits ? buf + sizea : NULL), textb, (a_fits ? bufsize - sizea : 0)) + 1) : 0); if (! (a_fits && sizea + sizeb <= bufsize)) { bufsize = sizea + sizeb; if (bufsize < SIZE_MAX / 3) bufsize = bufsize * 3 / 2; free (allocated); buf = allocated = xmalloc (bufsize); if (texta < lima) strxfrm (buf, texta, sizea); if (textb < limb) strxfrm (buf + sizea, textb, sizeb); } /* Advance past NULs to the next part of each input string, exiting the loop if both strings are exhausted. When exiting the loop, prepare to finish off the tiebreaker comparison properly. */ if (texta < lima) texta += strlen (texta) + 1; if (textb < limb) textb += strlen (textb) + 1; if (! (texta < lima || textb < limb)) { lena = sizea; texta = buf; lenb = sizeb; textb = buf + sizea; break; } /* Accumulate the transformed data in the corresponding checksums. */ md5_process_bytes (buf, sizea, &s[0]); md5_process_bytes (buf + sizea, sizeb, &s[1]); /* Update the tiebreaker comparison of the transformed data. */ if (! xfrm_diff) { xfrm_diff = memcmp (buf, buf + sizea, MIN (sizea, sizeb)); if (! xfrm_diff) xfrm_diff = (sizea > sizeb) - (sizea < sizeb); } } } /* Compute and compare the checksums. */ md5_process_bytes (texta, lena, &s[0]); md5_finish_ctx (&s[0], dig[0]); md5_process_bytes (textb, lenb, &s[1]); md5_finish_ctx (&s[1], dig[1]); int diff = memcmp (dig[0], dig[1], sizeof dig[0]); /* Fall back on the tiebreaker if the checksums collide. */ if (! diff) { if (! xfrm_diff) { xfrm_diff = memcmp (texta, textb, MIN (lena, lenb)); if (! xfrm_diff) xfrm_diff = (lena > lenb) - (lena < lenb); } diff = xfrm_diff; } free (allocated); return diff; } /* Return the printable width of the block of memory starting at TEXT and ending just before LIM, counting each tab as one byte. FIXME: Should we generally be counting non printable chars? */ static size_t debug_width (char const *text, char const *lim) { size_t width = mbsnwidth (text, lim - text, 0); while (text < lim) width += (*text++ == '\t'); return width; } /* For debug mode, "underline" a key at the specified offset and screen width. */ static void mark_key (size_t offset, size_t width) { while (offset--) putchar (' '); if (!width) printf (_("^ no match for key\n")); else { do putchar ('_'); while (--width); putchar ('\n'); } } /* Return true if KEY is a numeric key. */ static inline bool key_numeric (struct keyfield const *key) { return key->numeric || key->general_numeric || key->human_numeric; } /* For LINE, output a debugging line that underlines KEY in LINE. If KEY is null, underline the whole line. */ static void debug_key (struct line const *line, struct keyfield const *key) { char *text = line->text; char *beg = text; char *lim = text + line->length - 1; if (key) { if (key->sword != SIZE_MAX) beg = begfield (line, key); if (key->eword != SIZE_MAX) lim = limfield (line, key); if ((key->skipsblanks && key->sword == SIZE_MAX) || key->month || key_numeric (key)) { char saved = *lim; *lim = '\0'; while (blanks[to_uchar (*beg)]) beg++; char *tighter_lim = beg; if (lim < beg) tighter_lim = lim; else if (key->month) getmonth (beg, &tighter_lim); else if (key->general_numeric) ignore_value (strtold (beg, &tighter_lim)); else if (key->numeric || key->human_numeric) { char const *p = beg + (beg < lim && *beg == '-'); unsigned char max_digit = traverse_raw_number (&p); if ('0' <= max_digit) { unsigned char ch = *p; tighter_lim = (char *) p + (key->human_numeric && unit_order[ch]); } } else tighter_lim = lim; *lim = saved; lim = tighter_lim; } } size_t offset = debug_width (text, beg); size_t width = debug_width (beg, lim); mark_key (offset, width); } /* Debug LINE by underlining its keys. */ static void debug_line (struct line const *line) { struct keyfield const *key = keylist; do debug_key (line, key); while (key && ((key = key->next) || ! (unique || stable))); } /* Return whether sorting options specified for key. */ static bool default_key_compare (struct keyfield const *key) { return ! (key->ignore || key->translate || key->skipsblanks || key->skipeblanks || key_numeric (key) || key->month || key->version || key->random /* || key->reverse */ ); } /* Convert a key to the short options used to specify it. */ static void key_to_opts (struct keyfield const *key, char *opts) { if (key->skipsblanks || key->skipeblanks) *opts++ = 'b';/* either disables global -b */ if (key->ignore == nondictionary) *opts++ = 'd'; if (key->translate) *opts++ = 'f'; if (key->general_numeric) *opts++ = 'g'; if (key->human_numeric) *opts++ = 'h'; if (key->ignore == nonprinting) *opts++ = 'i'; if (key->month) *opts++ = 'M'; if (key->numeric) *opts++ = 'n'; if (key->random) *opts++ = 'R'; if (key->reverse) *opts++ = 'r'; if (key->version) *opts++ = 'V'; *opts = '\0'; } /* Output data independent key warnings to stderr. */ static void key_warnings (struct keyfield const *gkey, bool gkey_only) { struct keyfield const *key; struct keyfield ugkey = *gkey; unsigned long keynum = 1; for (key = keylist; key; key = key->next, keynum++) { if (key->traditional_used) { size_t sword = key->sword; size_t eword = key->eword; char tmp[INT_BUFSIZE_BOUND (uintmax_t)]; /* obsolescent syntax +A.x -B.y is equivalent to: -k A+1.x+1,B.y (when y = 0) -k A+1.x+1,B+1.y (when y > 0) */ char obuf[INT_BUFSIZE_BOUND (sword) * 2 + 4]; /* +# -# */ char nbuf[INT_BUFSIZE_BOUND (sword) * 2 + 5]; /* -k #,# */ char *po = obuf; char *pn = nbuf; if (sword == SIZE_MAX) sword++; po = stpcpy (stpcpy (po, "+"), umaxtostr (sword, tmp)); pn = stpcpy (stpcpy (pn, "-k "), umaxtostr (sword + 1, tmp)); if (key->eword != SIZE_MAX) { stpcpy (stpcpy (po, " -"), umaxtostr (eword + 1, tmp)); stpcpy (stpcpy (pn, ","), umaxtostr (eword + 1 + (key->echar == SIZE_MAX), tmp)); } error (0, 0, _("obsolescent key %s used; consider %s instead"), quote_n (0, obuf), quote_n (1, nbuf)); } /* Warn about field specs that will never match. */ bool zero_width = key->sword != SIZE_MAX && key->eword < key->sword; if (zero_width) error (0, 0, _("key %lu has zero width and will be ignored"), keynum); /* Warn about significant leading blanks. */ bool implicit_skip = key_numeric (key) || key->month; bool line_offset = key->eword == 0 && key->echar != 0; /* -k1.x,1.y */ if (!zero_width && !gkey_only && tab == TAB_DEFAULT && !line_offset && ((!key->skipsblanks && !implicit_skip) || (!key->skipsblanks && key->schar) || (!key->skipeblanks && key->echar))) error (0, 0, _("leading blanks are significant in key %lu; " "consider also specifying 'b'"), keynum); /* Warn about numeric comparisons spanning fields, as field delimiters could be interpreted as part of the number (maybe only in other locales). */ if (!gkey_only && key_numeric (key)) { size_t sword = key->sword + 1; size_t eword = key->eword + 1; if (!sword) sword++; if (!eword || sword < eword) error (0, 0, _("key %lu is numeric and spans multiple fields"), keynum); } /* Flag global options not copied or specified in any key. */ if (ugkey.ignore && (ugkey.ignore == key->ignore)) ugkey.ignore = NULL; if (ugkey.translate && (ugkey.translate == key->translate)) ugkey.translate = NULL; ugkey.skipsblanks &= !key->skipsblanks; ugkey.skipeblanks &= !key->skipeblanks; ugkey.month &= !key->month; ugkey.numeric &= !key->numeric; ugkey.general_numeric &= !key->general_numeric; ugkey.human_numeric &= !key->human_numeric; ugkey.random &= !key->random; ugkey.version &= !key->version; ugkey.reverse &= !key->reverse; } /* Warn about ignored global options flagged above. This clears all flags if UGKEY is the only one in the list. */ if (!default_key_compare (&ugkey) || (ugkey.reverse && (stable || unique) && keylist)) { bool ugkey_reverse = ugkey.reverse; if (!(stable || unique)) ugkey.reverse = false; /* The following is too big, but guaranteed to be "big enough". */ char opts[sizeof short_options]; key_to_opts (&ugkey, opts); error (0, 0, ngettext ("option '-%s' is ignored", "options '-%s' are ignored", select_plural (strlen (opts))), opts); ugkey.reverse = ugkey_reverse; } if (ugkey.reverse && !(stable || unique) && keylist) error (0, 0, _("option '-r' only applies to last-resort comparison")); } /* Compare two lines A and B trying every key in sequence until there are no more keys or a difference is found. */ static int keycompare (struct line const *a, struct line const *b) { struct keyfield *key = keylist; /* For the first iteration only, the key positions have been precomputed for us. */ char *texta = a->keybeg; char *textb = b->keybeg; char *lima = a->keylim; char *limb = b->keylim; int diff; while (true) { char const *translate = key->translate; bool const *ignore = key->ignore; /* Treat field ends before field starts as empty fields. */ lima = MAX (texta, lima); limb = MAX (textb, limb); /* Find the lengths. */ size_t lena = lima - texta; size_t lenb = limb - textb; if (hard_LC_COLLATE || key_numeric (key) || key->month || key->random || key->version) { char *ta; char *tb; size_t tlena; size_t tlenb; char enda IF_LINT (= 0); char endb IF_LINT (= 0); void *allocated IF_LINT (= NULL); char stackbuf[4000]; if (ignore || translate) { /* Compute with copies of the keys, which are the result of translating or ignoring characters, and which need their own storage. */ size_t i; /* Allocate space for copies. */ size_t size = lena + 1 + lenb + 1; if (size <= sizeof stackbuf) ta = stackbuf, allocated = NULL; else ta = allocated = xmalloc (size); tb = ta + lena + 1; /* Put into each copy a version of the key in which the requested characters are ignored or translated. */ for (tlena = i = 0; i < lena; i++) if (! (ignore && ignore[to_uchar (texta[i])])) ta[tlena++] = (translate ? translate[to_uchar (texta[i])] : texta[i]); ta[tlena] = '\0'; for (tlenb = i = 0; i < lenb; i++) if (! (ignore && ignore[to_uchar (textb[i])])) tb[tlenb++] = (translate ? translate[to_uchar (textb[i])] : textb[i]); tb[tlenb] = '\0'; } else { /* Use the keys in-place, temporarily null-terminated. */ ta = texta; tlena = lena; enda = ta[tlena]; ta[tlena] = '\0'; tb = textb; tlenb = lenb; endb = tb[tlenb]; tb[tlenb] = '\0'; } if (key->numeric) diff = numcompare (ta, tb); else if (key->general_numeric) diff = general_numcompare (ta, tb); else if (key->human_numeric) diff = human_numcompare (ta, tb); else if (key->month) diff = getmonth (ta, NULL) - getmonth (tb, NULL); else if (key->random) diff = compare_random (ta, tlena, tb, tlenb); else if (key->version) diff = filevercmp (ta, tb); else { /* Locale-dependent string sorting. This is slower than C-locale sorting, which is implemented below. */ if (tlena == 0) diff = - NONZERO (tlenb); else if (tlenb == 0) diff = 1; else diff = xmemcoll0 (ta, tlena + 1, tb, tlenb + 1); } if (ignore || translate) free (allocated); else { ta[tlena] = enda; tb[tlenb] = endb; } } else if (ignore) { #define CMP_WITH_IGNORE(A, B) \ do \ { \ while (true) \ { \ while (texta < lima && ignore[to_uchar (*texta)]) \ ++texta; \ while (textb < limb && ignore[to_uchar (*textb)]) \ ++textb; \ if (! (texta < lima && textb < limb)) \ break; \ diff = to_uchar (A) - to_uchar (B); \ if (diff) \ goto not_equal; \ ++texta; \ ++textb; \ } \ \ diff = (texta < lima) - (textb < limb); \ } \ while (0) if (translate) CMP_WITH_IGNORE (translate[to_uchar (*texta)], translate[to_uchar (*textb)]); else CMP_WITH_IGNORE (*texta, *textb); } else if (lena == 0) diff = - NONZERO (lenb); else if (lenb == 0) goto greater; else { if (translate) { while (texta < lima && textb < limb) { diff = (to_uchar (translate[to_uchar (*texta++)]) - to_uchar (translate[to_uchar (*textb++)])); if (diff) goto not_equal; } } else { diff = memcmp (texta, textb, MIN (lena, lenb)); if (diff) goto not_equal; } diff = lena < lenb ? -1 : lena != lenb; } if (diff) goto not_equal; key = key->next; if (! key) break; /* Find the beginning and limit of the next field. */ if (key->eword != SIZE_MAX) lima = limfield (a, key), limb = limfield (b, key); else lima = a->text + a->length - 1, limb = b->text + b->length - 1; if (key->sword != SIZE_MAX) texta = begfield (a, key), textb = begfield (b, key); else { texta = a->text, textb = b->text; if (key->skipsblanks) { while (texta < lima && blanks[to_uchar (*texta)]) ++texta; while (textb < limb && blanks[to_uchar (*textb)]) ++textb; } } } return 0; greater: diff = 1; not_equal: return key->reverse ? -diff : diff; } /* Compare two lines A and B, returning negative, zero, or positive depending on whether A compares less than, equal to, or greater than B. */ static int compare (struct line const *a, struct line const *b) { int diff; size_t alen, blen; /* First try to compare on the specified keys (if any). The only two cases with no key at all are unadorned sort, and unadorned sort -r. */ if (keylist) { diff = keycompare (a, b); if (diff || unique || stable) return diff; } /* If the keys all compare equal (or no keys were specified) fall through to the default comparison. */ alen = a->length - 1, blen = b->length - 1; if (alen == 0) diff = - NONZERO (blen); else if (blen == 0) diff = 1; else if (hard_LC_COLLATE) { /* xmemcoll0 is a performance enhancement as it will not unconditionally write '\0' after the passed in buffers, which was seen to give around a 3% increase in performance for short lines. */ diff = xmemcoll0 (a->text, alen + 1, b->text, blen + 1); } else if (! (diff = memcmp (a->text, b->text, MIN (alen, blen)))) diff = alen < blen ? -1 : alen != blen; return reverse ? -diff : diff; } /* Write LINE to output stream FP; the output file's name is OUTPUT_FILE if OUTPUT_FILE is non-null, and is the standard output otherwise. If debugging is enabled and FP is standard output, append some debugging information. */ static void write_line (struct line const *line, FILE *fp, char const *output_file) { char *buf = line->text; size_t n_bytes = line->length; char *ebuf = buf + n_bytes; if (!output_file && debug) { /* Convert TAB to '>' and EOL to \n, and then output debugging info. */ char const *c = buf; while (c < ebuf) { char wc = *c++; if (wc == '\t') wc = '>'; else if (c == ebuf) wc = '\n'; if (fputc (wc, fp) == EOF) sort_die (_("write failed"), output_file); } debug_line (line); } else { ebuf[-1] = eolchar; if (fwrite (buf, 1, n_bytes, fp) != n_bytes) sort_die (_("write failed"), output_file); ebuf[-1] = '\0'; } } /* Check that the lines read from FILE_NAME come in order. Return true if they are in order. If CHECKONLY == 'c', also print a diagnostic (FILE_NAME, line number, contents of line) to stderr if they are not in order. */ static bool check (char const *file_name, char checkonly) { FILE *fp = xfopen (file_name, "r"); struct buffer buf; /* Input buffer. */ struct line temp; /* Copy of previous line. */ size_t alloc = 0; uintmax_t line_number = 0; struct keyfield const *key = keylist; bool nonunique = ! unique; bool ordered = true; initbuf (&buf, sizeof (struct line), MAX (merge_buffer_size, sort_size)); temp.text = NULL; while (fillbuf (&buf, fp, file_name)) { struct line const *line = buffer_linelim (&buf); struct line const *linebase = line - buf.nlines; /* Make sure the line saved from the old buffer contents is less than or equal to the first line of the new buffer. */ if (alloc && nonunique <= compare (&temp, line - 1)) { found_disorder: { if (checkonly == 'c') { struct line const *disorder_line = line - 1; uintmax_t disorder_line_number = buffer_linelim (&buf) - disorder_line + line_number; char hr_buf[INT_BUFSIZE_BOUND (disorder_line_number)]; fprintf (stderr, _("%s: %s:%s: disorder: "), program_name, file_name, umaxtostr (disorder_line_number, hr_buf)); write_line (disorder_line, stderr, _("standard error")); } ordered = false; break; } } /* Compare each line in the buffer with its successor. */ while (linebase < --line) if (nonunique <= compare (line, line - 1)) goto found_disorder; line_number += buf.nlines; /* Save the last line of the buffer. */ if (alloc < line->length) { do { alloc *= 2; if (! alloc) { alloc = line->length; break; } } while (alloc < line->length); free (temp.text); temp.text = xmalloc (alloc); } memcpy (temp.text, line->text, line->length); temp.length = line->length; if (key) { temp.keybeg = temp.text + (line->keybeg - line->text); temp.keylim = temp.text + (line->keylim - line->text); } } xfclose (fp, file_name); free (buf.buf); free (temp.text); return ordered; } /* Open FILES (there are NFILES of them) and store the resulting array of stream pointers into (*PFPS). Allocate the array. Return the number of successfully opened files, setting errno if this value is less than NFILES. */ static size_t open_input_files (struct sortfile *files, size_t nfiles, FILE ***pfps) { FILE **fps = *pfps = xnmalloc (nfiles, sizeof *fps); int i; /* Open as many input files as we can. */ for (i = 0; i < nfiles; i++) { fps[i] = (files[i].temp && files[i].temp->state != UNCOMPRESSED ? open_temp (files[i].temp) : stream_open (files[i].name, "r")); if (!fps[i]) break; } return i; } /* Merge lines from FILES onto OFP. NTEMPS is the number of temporary files (all of which are at the start of the FILES array), and NFILES is the number of files; 0 <= NTEMPS <= NFILES <= NMERGE. FPS is the vector of open stream corresponding to the files. Close input and output streams before returning. OUTPUT_FILE gives the name of the output file. If it is NULL, the output file is standard output. */ static void mergefps (struct sortfile *files, size_t ntemps, size_t nfiles, FILE *ofp, char const *output_file, FILE **fps) { struct buffer *buffer = xnmalloc (nfiles, sizeof *buffer); /* Input buffers for each file. */ struct line saved; /* Saved line storage for unique check. */ struct line const *savedline = NULL; /* &saved if there is a saved line. */ size_t savealloc = 0; /* Size allocated for the saved line. */ struct line const **cur = xnmalloc (nfiles, sizeof *cur); /* Current line in each line table. */ struct line const **base = xnmalloc (nfiles, sizeof *base); /* Base of each line table. */ size_t *ord = xnmalloc (nfiles, sizeof *ord); /* Table representing a permutation of fps, such that cur[ord[0]] is the smallest line and will be next output. */ size_t i; size_t j; size_t t; struct keyfield const *key = keylist; saved.text = NULL; /* Read initial lines from each input file. */ for (i = 0; i < nfiles; ) { initbuf (&buffer[i], sizeof (struct line), MAX (merge_buffer_size, sort_size / nfiles)); if (fillbuf (&buffer[i], fps[i], files[i].name)) { struct line const *linelim = buffer_linelim (&buffer[i]); cur[i] = linelim - 1; base[i] = linelim - buffer[i].nlines; i++; } else { /* fps[i] is empty; eliminate it from future consideration. */ xfclose (fps[i], files[i].name); if (i < ntemps) { ntemps--; zaptemp (files[i].name); } free (buffer[i].buf); --nfiles; for (j = i; j < nfiles; ++j) { files[j] = files[j + 1]; fps[j] = fps[j + 1]; } } } /* Set up the ord table according to comparisons among input lines. Since this only reorders two items if one is strictly greater than the other, it is stable. */ for (i = 0; i < nfiles; ++i) ord[i] = i; for (i = 1; i < nfiles; ++i) if (0 < compare (cur[ord[i - 1]], cur[ord[i]])) t = ord[i - 1], ord[i - 1] = ord[i], ord[i] = t, i = 0; /* Repeatedly output the smallest line until no input remains. */ while (nfiles) { struct line const *smallest = cur[ord[0]]; /* If uniquified output is turned on, output only the first of an identical series of lines. */ if (unique) { if (savedline && compare (savedline, smallest)) { savedline = NULL; write_line (&saved, ofp, output_file); } if (!savedline) { savedline = &saved; if (savealloc < smallest->length) { do if (! savealloc) { savealloc = smallest->length; break; } while ((savealloc *= 2) < smallest->length); free (saved.text); saved.text = xmalloc (savealloc); } saved.length = smallest->length; memcpy (saved.text, smallest->text, saved.length); if (key) { saved.keybeg = saved.text + (smallest->keybeg - smallest->text); saved.keylim = saved.text + (smallest->keylim - smallest->text); } } } else write_line (smallest, ofp, output_file); /* Check if we need to read more lines into core. */ if (base[ord[0]] < smallest) cur[ord[0]] = smallest - 1; else { if (fillbuf (&buffer[ord[0]], fps[ord[0]], files[ord[0]].name)) { struct line const *linelim = buffer_linelim (&buffer[ord[0]]); cur[ord[0]] = linelim - 1; base[ord[0]] = linelim - buffer[ord[0]].nlines; } else { /* We reached EOF on fps[ord[0]]. */ for (i = 1; i < nfiles; ++i) if (ord[i] > ord[0]) --ord[i]; --nfiles; xfclose (fps[ord[0]], files[ord[0]].name); if (ord[0] < ntemps) { ntemps--; zaptemp (files[ord[0]].name); } free (buffer[ord[0]].buf); for (i = ord[0]; i < nfiles; ++i) { fps[i] = fps[i + 1]; files[i] = files[i + 1]; buffer[i] = buffer[i + 1]; cur[i] = cur[i + 1]; base[i] = base[i + 1]; } for (i = 0; i < nfiles; ++i) ord[i] = ord[i + 1]; continue; } } /* The new line just read in may be larger than other lines already in main memory; push it back in the queue until we encounter a line larger than it. Optimize for the common case where the new line is smallest. */ { size_t lo = 1; size_t hi = nfiles; size_t probe = lo; size_t ord0 = ord[0]; size_t count_of_smaller_lines; while (lo < hi) { int cmp = compare (cur[ord0], cur[ord[probe]]); if (cmp < 0 || (cmp == 0 && ord0 < ord[probe])) hi = probe; else lo = probe + 1; probe = (lo + hi) / 2; } count_of_smaller_lines = lo - 1; for (j = 0; j < count_of_smaller_lines; j++) ord[j] = ord[j + 1]; ord[count_of_smaller_lines] = ord0; } } if (unique && savedline) { write_line (&saved, ofp, output_file); free (saved.text); } xfclose (ofp, output_file); free (fps); free (buffer); free (ord); free (base); free (cur); } /* Merge lines from FILES onto OFP. NTEMPS is the number of temporary files (all of which are at the start of the FILES array), and NFILES is the number of files; 0 <= NTEMPS <= NFILES <= NMERGE. Close input and output files before returning. OUTPUT_FILE gives the name of the output file. Return the number of files successfully merged. This number can be less than NFILES if we ran low on file descriptors, but in this case it is never less than 2. */ static size_t mergefiles (struct sortfile *files, size_t ntemps, size_t nfiles, FILE *ofp, char const *output_file) { FILE **fps; size_t nopened = open_input_files (files, nfiles, &fps); if (nopened < nfiles && nopened < 2) sort_die (_("open failed"), files[nopened].name); mergefps (files, ntemps, nopened, ofp, output_file, fps); return nopened; } /* Merge into T (of size NLINES) the two sorted arrays of lines LO (with NLINES / 2 members), and T - (NLINES / 2) (with NLINES - NLINES / 2 members). T and LO point just past their respective arrays, and the arrays are in reverse order. NLINES must be at least 2. */ static void mergelines (struct line *restrict t, size_t nlines, struct line const *restrict lo) { size_t nlo = nlines / 2; size_t nhi = nlines - nlo; struct line *hi = t - nlo; while (true) if (compare (lo - 1, hi - 1) <= 0) { *--t = *--lo; if (! --nlo) { /* HI must equal T now, and there is no need to copy from HI to T. */ return; } } else { *--t = *--hi; if (! --nhi) { do *--t = *--lo; while (--nlo); return; } } } /* Sort the array LINES with NLINES members, using TEMP for temporary space. Do this all within one thread. NLINES must be at least 2. If TO_TEMP, put the sorted output into TEMP, and TEMP is as large as LINES. Otherwise the sort is in-place and TEMP is half-sized. The input and output arrays are in reverse order, and LINES and TEMP point just past the end of their respective arrays. Use a recursive divide-and-conquer algorithm, in the style suggested by Knuth volume 3 (2nd edition), exercise 5.2.4-23. Use the optimization suggested by exercise 5.2.4-10; this requires room for only 1.5*N lines, rather than the usual 2*N lines. Knuth writes that this memory optimization was originally published by D. A. Bell, Comp J. 1 (1958), 75. */ static void sequential_sort (struct line *restrict lines, size_t nlines, struct line *restrict temp, bool to_temp) { if (nlines == 2) { /* Declare 'swap' as int, not bool, to work around a bug in the IBM xlc 6.0.0.0 compiler in 64-bit mode. */ int swap = (0 < compare (&lines[-1], &lines[-2])); if (to_temp) { temp[-1] = lines[-1 - swap]; temp[-2] = lines[-2 + swap]; } else if (swap) { temp[-1] = lines[-1]; lines[-1] = lines[-2]; lines[-2] = temp[-1]; } } else { size_t nlo = nlines / 2; size_t nhi = nlines - nlo; struct line *lo = lines; struct line *hi = lines - nlo; sequential_sort (hi, nhi, temp - (to_temp ? nlo : 0), to_temp); if (1 < nlo) sequential_sort (lo, nlo, temp, !to_temp); else if (!to_temp) temp[-1] = lo[-1]; struct line *dest; struct line const *sorted_lo; if (to_temp) { dest = temp; sorted_lo = lines; } else { dest = lines; sorted_lo = temp; } mergelines (dest, nlines, sorted_lo); } } static struct merge_node *init_node (struct merge_node *restrict, struct merge_node *restrict, struct line *, size_t, size_t, bool); /* Create and return a merge tree for NTHREADS threads, sorting NLINES lines, with destination DEST. */ static struct merge_node * merge_tree_init (size_t nthreads, size_t nlines, struct line *dest) { struct merge_node *merge_tree = xmalloc (2 * sizeof *merge_tree * nthreads); struct merge_node *root = merge_tree; root->lo = root->hi = root->end_lo = root->end_hi = NULL; root->dest = NULL; root->nlo = root->nhi = nlines; root->parent = NULL; root->level = MERGE_END; root->queued = false; pthread_mutex_init (&root->lock, NULL); init_node (root, root + 1, dest, nthreads, nlines, false); return merge_tree; } /* Destroy the merge tree. */ static void merge_tree_destroy (size_t nthreads, struct merge_node *merge_tree) { size_t n_nodes = nthreads * 2; struct merge_node *node = merge_tree; while (n_nodes--) { pthread_mutex_destroy (&node->lock); node++; } free (merge_tree); } /* Initialize a merge tree node and its descendants. The node's parent is PARENT. The node and its descendants are taken from the array of nodes NODE_POOL. Their destination starts at DEST; they will consume NTHREADS threads. The total number of sort lines is TOTAL_LINES. IS_LO_CHILD is true if the node is the low child of its parent. */ static struct merge_node * init_node (struct merge_node *restrict parent, struct merge_node *restrict node_pool, struct line *dest, size_t nthreads, size_t total_lines, bool is_lo_child) { size_t nlines = (is_lo_child ? parent->nlo : parent->nhi); size_t nlo = nlines / 2; size_t nhi = nlines - nlo; struct line *lo = dest - total_lines; struct line *hi = lo - nlo; struct line **parent_end = (is_lo_child ? &parent->end_lo : &parent->end_hi); struct merge_node *node = node_pool++; node->lo = node->end_lo = lo; node->hi = node->end_hi = hi; node->dest = parent_end; node->nlo = nlo; node->nhi = nhi; node->parent = parent; node->level = parent->level + 1; node->queued = false; pthread_mutex_init (&node->lock, NULL); if (nthreads > 1) { size_t lo_threads = nthreads / 2; size_t hi_threads = nthreads - lo_threads; node->lo_child = node_pool; node_pool = init_node (node, node_pool, lo, lo_threads, total_lines, true); node->hi_child = node_pool; node_pool = init_node (node, node_pool, hi, hi_threads, total_lines, false); } else { node->lo_child = NULL; node->hi_child = NULL; } return node_pool; } /* Compare two merge nodes A and B for priority. */ static int compare_nodes (void const *a, void const *b) { struct merge_node const *nodea = a; struct merge_node const *nodeb = b; if (nodea->level == nodeb->level) return (nodea->nlo + nodea->nhi) < (nodeb->nlo + nodeb->nhi); return nodea->level < nodeb->level; } /* Lock a merge tree NODE. */ static inline void lock_node (struct merge_node *node) { pthread_mutex_lock (&node->lock); } /* Unlock a merge tree NODE. */ static inline void unlock_node (struct merge_node *node) { pthread_mutex_unlock (&node->lock); } /* Destroy merge QUEUE. */ static void queue_destroy (struct merge_node_queue *queue) { heap_free (queue->priority_queue); pthread_cond_destroy (&queue->cond); pthread_mutex_destroy (&queue->mutex); } /* Initialize merge QUEUE, allocating space suitable for a maximum of NTHREADS threads. */ static void queue_init (struct merge_node_queue *queue, size_t nthreads) { /* Though it's highly unlikely all nodes are in the heap at the same time, the heap should accommodate all of them. Counting a NULL dummy head for the heap, reserve 2 * NTHREADS nodes. */ queue->priority_queue = heap_alloc (compare_nodes, 2 * nthreads); pthread_mutex_init (&queue->mutex, NULL); pthread_cond_init (&queue->cond, NULL); } /* Insert NODE into QUEUE. The caller either holds a lock on NODE, or does not need to lock NODE. */ static void queue_insert (struct merge_node_queue *queue, struct merge_node *node) { pthread_mutex_lock (&queue->mutex); heap_insert (queue->priority_queue, node); node->queued = true; pthread_cond_signal (&queue->cond); pthread_mutex_unlock (&queue->mutex); } /* Pop the top node off the priority QUEUE, lock the node, return it. */ static struct merge_node * queue_pop (struct merge_node_queue *queue) { struct merge_node *node; pthread_mutex_lock (&queue->mutex); while (! (node = heap_remove_top (queue->priority_queue))) pthread_cond_wait (&queue->cond, &queue->mutex); pthread_mutex_unlock (&queue->mutex); lock_node (node); node->queued = false; return node; } /* Output LINE to TFP, unless -u is specified and the line compares equal to the previous line. TEMP_OUTPUT is the name of TFP, or is null if TFP is standard output. This function does not save the line for comparison later, so it is appropriate only for internal sort. */ static void write_unique (struct line const *line, FILE *tfp, char const *temp_output) { if (unique) { if (saved_line.text && ! compare (line, &saved_line)) return; saved_line = *line; } write_line (line, tfp, temp_output); } /* Merge the lines currently available to a NODE in the binary merge tree. Merge a number of lines appropriate for this merge level, assuming TOTAL_LINES is the total number of lines. If merging at the top level, send output to TFP. TEMP_OUTPUT is the name of TFP, or is null if TFP is standard output. */ static void mergelines_node (struct merge_node *restrict node, size_t total_lines, FILE *tfp, char const *temp_output) { struct line *lo_orig = node->lo; struct line *hi_orig = node->hi; size_t to_merge = MAX_MERGE (total_lines, node->level); size_t merged_lo; size_t merged_hi; if (node->level > MERGE_ROOT) { /* Merge to destination buffer. */ struct line *dest = *node->dest; while (node->lo != node->end_lo && node->hi != node->end_hi && to_merge--) if (compare (node->lo - 1, node->hi - 1) <= 0) *--dest = *--node->lo; else *--dest = *--node->hi; merged_lo = lo_orig - node->lo; merged_hi = hi_orig - node->hi; if (node->nhi == merged_hi) while (node->lo != node->end_lo && to_merge--) *--dest = *--node->lo; else if (node->nlo == merged_lo) while (node->hi != node->end_hi && to_merge--) *--dest = *--node->hi; *node->dest = dest; } else { /* Merge directly to output. */ while (node->lo != node->end_lo && node->hi != node->end_hi && to_merge--) { if (compare (node->lo - 1, node->hi - 1) <= 0) write_unique (--node->lo, tfp, temp_output); else write_unique (--node->hi, tfp, temp_output); } merged_lo = lo_orig - node->lo; merged_hi = hi_orig - node->hi; if (node->nhi == merged_hi) { while (node->lo != node->end_lo && to_merge--) write_unique (--node->lo, tfp, temp_output); } else if (node->nlo == merged_lo) { while (node->hi != node->end_hi && to_merge--) write_unique (--node->hi, tfp, temp_output); } } /* Update NODE. */ merged_lo = lo_orig - node->lo; merged_hi = hi_orig - node->hi; node->nlo -= merged_lo; node->nhi -= merged_hi; } /* Into QUEUE, insert NODE if it is not already queued, and if one of NODE's children has available lines and the other either has available lines or has exhausted its lines. */ static void queue_check_insert (struct merge_node_queue *queue, struct merge_node *node) { if (! node->queued) { bool lo_avail = (node->lo - node->end_lo) != 0; bool hi_avail = (node->hi - node->end_hi) != 0; if (lo_avail ? hi_avail || ! node->nhi : hi_avail && ! node->nlo) queue_insert (queue, node); } } /* Into QUEUE, insert NODE's parent if the parent can now be worked on. */ static void queue_check_insert_parent (struct merge_node_queue *queue, struct merge_node *node) { if (node->level > MERGE_ROOT) { lock_node (node->parent); queue_check_insert (queue, node->parent); unlock_node (node->parent); } else if (node->nlo + node->nhi == 0) { /* If the MERGE_ROOT NODE has finished merging, insert the MERGE_END node. */ queue_insert (queue, node->parent); } } /* Repeatedly pop QUEUE for a node with lines to merge, and merge at least some of those lines, until the MERGE_END node is popped. TOTAL_LINES is the total number of lines. If merging at the top level, send output to TFP. TEMP_OUTPUT is the name of TFP, or is null if TFP is standard output. */ static void merge_loop (struct merge_node_queue *queue, size_t total_lines, FILE *tfp, char const *temp_output) { while (1) { struct merge_node *node = queue_pop (queue); if (node->level == MERGE_END) { unlock_node (node); /* Reinsert so other threads can pop it. */ queue_insert (queue, node); break; } mergelines_node (node, total_lines, tfp, temp_output); queue_check_insert (queue, node); queue_check_insert_parent (queue, node); unlock_node (node); } } static void sortlines (struct line *restrict, size_t, size_t, struct merge_node *, struct merge_node_queue *, FILE *, char const *); /* Thread arguments for sortlines_thread. */ struct thread_args { /* Source, i.e., the array of lines to sort. This points just past the end of the array. */ struct line *lines; /* Number of threads to use. If 0 or 1, sort single-threaded. */ size_t nthreads; /* Number of lines in LINES and DEST. */ size_t const total_lines; /* Merge node. Lines from this node and this node's sibling will merged to this node's parent. */ struct merge_node *const node; /* The priority queue controlling available work for the entire internal sort. */ struct merge_node_queue *const queue; /* If at the top level, the file to output to, and the file's name. If the file is standard output, the file's name is null. */ FILE *tfp; char const *output_temp; }; /* Like sortlines, except with a signature acceptable to pthread_create. */ static void * sortlines_thread (void *data) { struct thread_args const *args = data; sortlines (args->lines, args->nthreads, args->total_lines, args->node, args->queue, args->tfp, args->output_temp); return NULL; } /* Sort lines, possibly in parallel. The arguments are as in struct thread_args above. The algorithm has three phases: node creation, sequential sort, and binary merge. During node creation, sortlines recursively visits each node in the binary merge tree and creates a NODE structure corresponding to all the future line merging NODE is responsible for. For each call to sortlines, half the available threads are assigned to each recursive call, until a leaf node having only 1 available thread is reached. Each leaf node then performs two sequential sorts, one on each half of the lines it is responsible for. It records in its NODE structure that there are two sorted sublists available to merge from, and inserts its NODE into the priority queue. The binary merge phase then begins. Each thread drops into a loop where the thread retrieves a NODE from the priority queue, merges lines available to that NODE, and potentially insert NODE or its parent back into the queue if there are sufficient available lines for them to merge. This continues until all lines at all nodes of the merge tree have been merged. */ static void sortlines (struct line *restrict lines, size_t nthreads, size_t total_lines, struct merge_node *node, struct merge_node_queue *queue, FILE *tfp, char const *temp_output) { size_t nlines = node->nlo + node->nhi; /* Calculate thread arguments. */ size_t lo_threads = nthreads / 2; size_t hi_threads = nthreads - lo_threads; pthread_t thread; struct thread_args args = {lines, lo_threads, total_lines, node->lo_child, queue, tfp, temp_output}; if (nthreads > 1 && SUBTHREAD_LINES_HEURISTIC <= nlines && pthread_create (&thread, NULL, sortlines_thread, &args) == 0) { sortlines (lines - node->nlo, hi_threads, total_lines, node->hi_child, queue, tfp, temp_output); pthread_join (thread, NULL); } else { /* Nthreads = 1, this is a leaf NODE, or pthread_create failed. Sort with 1 thread. */ size_t nlo = node->nlo; size_t nhi = node->nhi; struct line *temp = lines - total_lines; if (1 < nhi) sequential_sort (lines - nlo, nhi, temp - nlo / 2, false); if (1 < nlo) sequential_sort (lines, nlo, temp, false); /* Update merge NODE. No need to lock yet. */ node->lo = lines; node->hi = lines - nlo; node->end_lo = lines - nlo; node->end_hi = lines - nlo - nhi; queue_insert (queue, node); merge_loop (queue, total_lines, tfp, temp_output); } } /* Scan through FILES[NTEMPS .. NFILES-1] looking for files that are the same as OUTFILE. If found, replace each with the same temporary copy that can be merged into OUTFILE without destroying OUTFILE before it is completely read. This temporary copy does not count as a merge temp, so don't worry about incrementing NTEMPS in the caller; final cleanup will remove it, not zaptemp. This test ensures that an otherwise-erroneous use like "sort -m -o FILE ... FILE ..." copies FILE before writing to it. It's not clear that POSIX requires this nicety. Detect common error cases, but don't try to catch obscure cases like "cat ... FILE ... | sort -m -o FILE" where traditional "sort" doesn't copy the input and where people should know that they're getting into trouble anyway. Catching these obscure cases would slow down performance in common cases. */ static void avoid_trashing_input (struct sortfile *files, size_t ntemps, size_t nfiles, char const *outfile) { struct tempnode *tempcopy = NULL; for (size_t i = ntemps; i < nfiles; i++) { bool is_stdin = STREQ (files[i].name, "-"); bool same; struct stat instat; if (outfile && STREQ (outfile, files[i].name) && !is_stdin) same = true; else { struct stat *outst = get_outstatus (); if (!outst) break; same = (((is_stdin ? fstat (STDIN_FILENO, &instat) : stat (files[i].name, &instat)) == 0) && SAME_INODE (instat, *outst)); } if (same) { if (! tempcopy) { FILE *tftp; tempcopy = create_temp (&tftp); mergefiles (&files[i], 0, 1, tftp, tempcopy->name); } files[i].name = tempcopy->name; files[i].temp = tempcopy; } } } /* Scan the input files to ensure all are accessible. Otherwise exit with a diagnostic. This will catch common issues with permissions etc. but will fail to notice issues where you can open but not read, like when a directory is specified on some systems. Catching these obscure cases could slow down performance in common cases. */ static void check_inputs (char *const *files, size_t nfiles) { for (size_t i = 0; i < nfiles; i++) { if (STREQ (files[i], "-")) continue; if (euidaccess (files[i], R_OK) != 0) sort_die (_("cannot read"), files[i]); } } /* Ensure a specified output file can be created or written to, and point stdout to it. Do not truncate the file. Exit with a diagnostic on failure. */ static void check_output (char const *outfile) { if (outfile) { int oflags = O_WRONLY | O_BINARY | O_CLOEXEC | O_CREAT; int outfd = open (outfile, oflags, MODE_RW_UGO); if (outfd < 0) sort_die (_("open failed"), outfile); move_fd (outfd, STDOUT_FILENO); } } /* Merge the input FILES. NTEMPS is the number of files at the start of FILES that are temporary; it is zero at the top level. NFILES is the total number of files. Put the output in OUTPUT_FILE; a null OUTPUT_FILE stands for standard output. */ static void merge (struct sortfile *files, size_t ntemps, size_t nfiles, char const *output_file) { while (nmerge < nfiles) { /* Number of input files processed so far. */ size_t in; /* Number of output files generated so far. */ size_t out; /* nfiles % NMERGE; this counts input files that are left over after all full-sized merges have been done. */ size_t remainder; /* Number of easily-available slots at the next loop iteration. */ size_t cheap_slots; /* Do as many NMERGE-size merges as possible. In the case that nmerge is bogus, increment by the maximum number of file descriptors allowed. */ for (out = in = 0; nmerge <= nfiles - in; out++) { FILE *tfp; struct tempnode *temp = create_temp (&tfp); size_t num_merged = mergefiles (&files[in], MIN (ntemps, nmerge), nmerge, tfp, temp->name); ntemps -= MIN (ntemps, num_merged); files[out].name = temp->name; files[out].temp = temp; in += num_merged; } remainder = nfiles - in; cheap_slots = nmerge - out % nmerge; if (cheap_slots < remainder) { /* So many files remain that they can't all be put into the last NMERGE-sized output window. Do one more merge. Merge as few files as possible, to avoid needless I/O. */ size_t nshortmerge = remainder - cheap_slots + 1; FILE *tfp; struct tempnode *temp = create_temp (&tfp); size_t num_merged = mergefiles (&files[in], MIN (ntemps, nshortmerge), nshortmerge, tfp, temp->name); ntemps -= MIN (ntemps, num_merged); files[out].name = temp->name; files[out++].temp = temp; in += num_merged; } /* Put the remaining input files into the last NMERGE-sized output window, so they will be merged in the next pass. */ memmove (&files[out], &files[in], (nfiles - in) * sizeof *files); ntemps += out; nfiles -= in - out; } avoid_trashing_input (files, ntemps, nfiles, output_file); /* We aren't guaranteed that this final mergefiles will work, therefore we try to merge into the output, and then merge as much as we can into a temp file if we can't. Repeat. */ while (true) { /* Merge directly into the output file if possible. */ FILE **fps; size_t nopened = open_input_files (files, nfiles, &fps); if (nopened == nfiles) { FILE *ofp = stream_open (output_file, "w"); if (ofp) { mergefps (files, ntemps, nfiles, ofp, output_file, fps); break; } if (errno != EMFILE || nopened <= 2) sort_die (_("open failed"), output_file); } else if (nopened <= 2) sort_die (_("open failed"), files[nopened].name); /* We ran out of file descriptors. Close one of the input files, to gain a file descriptor. Then create a temporary file with our spare file descriptor. Retry if that failed (e.g., some other process could open a file between the time we closed and tried to create). */ FILE *tfp; struct tempnode *temp; do { nopened--; xfclose (fps[nopened], files[nopened].name); temp = maybe_create_temp (&tfp, ! (nopened <= 2)); } while (!temp); /* Merge into the newly allocated temporary. */ mergefps (&files[0], MIN (ntemps, nopened), nopened, tfp, temp->name, fps); ntemps -= MIN (ntemps, nopened); files[0].name = temp->name; files[0].temp = temp; memmove (&files[1], &files[nopened], (nfiles - nopened) * sizeof *files); ntemps++; nfiles -= nopened - 1; } } /* Sort NFILES FILES onto OUTPUT_FILE. Use at most NTHREADS threads. */ static void sort (char *const *files, size_t nfiles, char const *output_file, size_t nthreads) { struct buffer buf; IF_LINT (buf.buf = NULL); size_t ntemps = 0; bool output_file_created = false; buf.alloc = 0; while (nfiles) { char const *temp_output; char const *file = *files; FILE *fp = xfopen (file, "r"); FILE *tfp; size_t bytes_per_line; if (nthreads > 1) { /* Get log P. */ size_t tmp = 1; size_t mult = 1; while (tmp < nthreads) { tmp *= 2; mult++; } bytes_per_line = (mult * sizeof (struct line)); } else bytes_per_line = sizeof (struct line) * 3 / 2; if (! buf.alloc) initbuf (&buf, bytes_per_line, sort_buffer_size (&fp, 1, files, nfiles, bytes_per_line)); buf.eof = false; files++; nfiles--; while (fillbuf (&buf, fp, file)) { struct line *line; if (buf.eof && nfiles && (bytes_per_line + 1 < (buf.alloc - buf.used - bytes_per_line * buf.nlines))) { /* End of file, but there is more input and buffer room. Concatenate the next input file; this is faster in the usual case. */ buf.left = buf.used; break; } saved_line.text = NULL; line = buffer_linelim (&buf); if (buf.eof && !nfiles && !ntemps && !buf.left) { xfclose (fp, file); tfp = xfopen (output_file, "w"); temp_output = output_file; output_file_created = true; } else { ++ntemps; temp_output = create_temp (&tfp)->name; } if (1 < buf.nlines) { struct merge_node_queue queue; queue_init (&queue, nthreads); struct merge_node *merge_tree = merge_tree_init (nthreads, buf.nlines, line); sortlines (line, nthreads, buf.nlines, merge_tree + 1, &queue, tfp, temp_output); #ifdef lint merge_tree_destroy (nthreads, merge_tree); queue_destroy (&queue); #endif } else write_unique (line - 1, tfp, temp_output); xfclose (tfp, temp_output); if (output_file_created) goto finish; } xfclose (fp, file); } finish: free (buf.buf); if (! output_file_created) { struct tempnode *node = temphead; struct sortfile *tempfiles = xnmalloc (ntemps, sizeof *tempfiles); for (size_t i = 0; node; i++) { tempfiles[i].name = node->name; tempfiles[i].temp = node; node = node->next; } merge (tempfiles, ntemps, ntemps, output_file); free (tempfiles); } reap_all (); } /* Insert a malloc'd copy of key KEY_ARG at the end of the key list. */ static void insertkey (struct keyfield *key_arg) { struct keyfield **p; struct keyfield *key = xmemdup (key_arg, sizeof *key); for (p = &keylist; *p; p = &(*p)->next) continue; *p = key; key->next = NULL; } /* Report a bad field specification SPEC, with extra info MSGID. */ static void badfieldspec (char const *, char const *) ATTRIBUTE_NORETURN; static void badfieldspec (char const *spec, char const *msgid) { die (SORT_FAILURE, 0, _("%s: invalid field specification %s"), _(msgid), quote (spec)); } /* Report incompatible options. */ static void incompatible_options (char const *) ATTRIBUTE_NORETURN; static void incompatible_options (char const *opts) { die (SORT_FAILURE, 0, _("options '-%s' are incompatible"), (opts)); } /* Check compatibility of ordering options. */ static void check_ordering_compatibility (void) { struct keyfield *key; for (key = keylist; key; key = key->next) if (1 < (key->numeric + key->general_numeric + key->human_numeric + key->month + (key->version | key->random | !!key->ignore))) { /* The following is too big, but guaranteed to be "big enough". */ char opts[sizeof short_options]; /* Clear flags we're not interested in. */ key->skipsblanks = key->skipeblanks = key->reverse = false; key_to_opts (key, opts); incompatible_options (opts); } } /* Parse the leading integer in STRING and store the resulting value (which must fit into size_t) into *VAL. Return the address of the suffix after the integer. If the value is too large, silently substitute SIZE_MAX. If MSGID is NULL, return NULL after failure; otherwise, report MSGID and exit on failure. */ static char const * parse_field_count (char const *string, size_t *val, char const *msgid) { char *suffix; uintmax_t n; switch (xstrtoumax (string, &suffix, 10, &n, "")) { case LONGINT_OK: case LONGINT_INVALID_SUFFIX_CHAR: *val = n; if (*val == n) break; FALLTHROUGH; case LONGINT_OVERFLOW: case LONGINT_OVERFLOW | LONGINT_INVALID_SUFFIX_CHAR: *val = SIZE_MAX; break; case LONGINT_INVALID: if (msgid) die (SORT_FAILURE, 0, _("%s: invalid count at start of %s"), _(msgid), quote (string)); return NULL; } return suffix; } /* Handle interrupts and hangups. */ static void sighandler (int sig) { if (! SA_NOCLDSTOP) signal (sig, SIG_IGN); cleanup (); signal (sig, SIG_DFL); raise (sig); } /* Set the ordering options for KEY specified in S. Return the address of the first character in S that is not a valid ordering option. BLANKTYPE is the kind of blanks that 'b' should skip. */ static char * set_ordering (char const *s, struct keyfield *key, enum blanktype blanktype) { while (*s) { switch (*s) { case 'b': if (blanktype == bl_start || blanktype == bl_both) key->skipsblanks = true; if (blanktype == bl_end || blanktype == bl_both) key->skipeblanks = true; break; case 'd': key->ignore = nondictionary; break; case 'f': key->translate = fold_toupper; break; case 'g': key->general_numeric = true; break; case 'h': key->human_numeric = true; break; case 'i': /* Option order should not matter, so don't let -i override -d. -d implies -i, but -i does not imply -d. */ if (! key->ignore) key->ignore = nonprinting; break; case 'M': key->month = true; break; case 'n': key->numeric = true; break; case 'R': key->random = true; break; case 'r': key->reverse = true; break; case 'V': key->version = true; break; default: return (char *) s; } ++s; } return (char *) s; } /* Initialize KEY. */ static struct keyfield * key_init (struct keyfield *key) { memset (key, 0, sizeof *key); key->eword = SIZE_MAX; return key; } int main (int argc, char **argv) { struct keyfield *key; struct keyfield key_buf; struct keyfield gkey; bool gkey_only = false; char const *s; int c = 0; char checkonly = 0; bool mergeonly = false; char *random_source = NULL; bool need_random = false; size_t nthreads = 0; size_t nfiles = 0; bool posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL); int posix_ver = posix2_version (); bool traditional_usage = ! (200112 <= posix_ver && posix_ver < 200809); char **files; char *files_from = NULL; struct Tokens tok; char const *outfile = NULL; bool locale_ok; initialize_main (&argc, &argv); set_program_name (argv[0]); locale_ok = !! setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); initialize_exit_failure (SORT_FAILURE); hard_LC_COLLATE = hard_locale (LC_COLLATE); #if HAVE_NL_LANGINFO hard_LC_TIME = hard_locale (LC_TIME); #endif /* Get locale's representation of the decimal point. */ { struct lconv const *locale = localeconv (); /* If the locale doesn't define a decimal point, or if the decimal point is multibyte, use the C locale's decimal point. FIXME: add support for multibyte decimal points. */ decimal_point = to_uchar (locale->decimal_point[0]); if (! decimal_point || locale->decimal_point[1]) decimal_point = '.'; /* FIXME: add support for multibyte thousands separators. */ thousands_sep = to_uchar (*locale->thousands_sep); if (! thousands_sep || locale->thousands_sep[1]) thousands_sep = -1; } have_read_stdin = false; inittables (); { size_t i; static int const sig[] = { /* The usual suspects. */ SIGALRM, SIGHUP, SIGINT, SIGPIPE, SIGQUIT, SIGTERM, #ifdef SIGPOLL SIGPOLL, #endif #ifdef SIGPROF SIGPROF, #endif #ifdef SIGVTALRM SIGVTALRM, #endif #ifdef SIGXCPU SIGXCPU, #endif #ifdef SIGXFSZ SIGXFSZ, #endif }; enum { nsigs = ARRAY_CARDINALITY (sig) }; #if SA_NOCLDSTOP struct sigaction act; sigemptyset (&caught_signals); for (i = 0; i < nsigs; i++) { sigaction (sig[i], NULL, &act); if (act.sa_handler != SIG_IGN) sigaddset (&caught_signals, sig[i]); } act.sa_handler = sighandler; act.sa_mask = caught_signals; act.sa_flags = 0; for (i = 0; i < nsigs; i++) if (sigismember (&caught_signals, sig[i])) sigaction (sig[i], &act, NULL); #else for (i = 0; i < nsigs; i++) if (signal (sig[i], SIG_IGN) != SIG_IGN) { signal (sig[i], sighandler); siginterrupt (sig[i], 1); } #endif } signal (SIGCHLD, SIG_DFL); /* Don't inherit CHLD handling from parent. */ /* The signal mask is known, so it is safe to invoke exit_cleanup. */ atexit (exit_cleanup); key_init (&gkey); gkey.sword = SIZE_MAX; files = xnmalloc (argc, sizeof *files); while (true) { /* Parse an operand as a file after "--" was seen; or if pedantic and a file was seen, unless the POSIX version is not 1003.1-2001 and -c was not seen and the operand is "-o FILE" or "-oFILE". */ int oi = -1; if (c == -1 || (posixly_correct && nfiles != 0 && ! (traditional_usage && ! checkonly && optind != argc && argv[optind][0] == '-' && argv[optind][1] == 'o' && (argv[optind][2] || optind + 1 != argc))) || ((c = getopt_long (argc, argv, short_options, long_options, &oi)) == -1)) { if (argc <= optind) break; files[nfiles++] = argv[optind++]; } else switch (c) { case 1: key = NULL; if (optarg[0] == '+') { bool minus_pos_usage = (optind != argc && argv[optind][0] == '-' && ISDIGIT (argv[optind][1])); traditional_usage |= minus_pos_usage && !posixly_correct; if (traditional_usage) { /* Treat +POS1 [-POS2] as a key if possible; but silently treat an operand as a file if it is not a valid +POS1. */ key = key_init (&key_buf); s = parse_field_count (optarg + 1, &key->sword, NULL); if (s && *s == '.') s = parse_field_count (s + 1, &key->schar, NULL); if (! (key->sword || key->schar)) key->sword = SIZE_MAX; if (! s || *set_ordering (s, key, bl_start)) key = NULL; else { if (minus_pos_usage) { char const *optarg1 = argv[optind++]; s = parse_field_count (optarg1 + 1, &key->eword, N_("invalid number after '-'")); /* When called with a non-NULL message ID, parse_field_count cannot return NULL. Tell static analysis tools that dereferencing S is safe. */ assert (s); if (*s == '.') s = parse_field_count (s + 1, &key->echar, N_("invalid number after '.'")); if (!key->echar && key->eword) { /* obsolescent syntax +A.x -B.y is equivalent to: -k A+1.x+1,B.y (when y = 0) -k A+1.x+1,B+1.y (when y > 0) So eword is decremented as in the -k case only when the end field (B) is specified and echar (y) is 0. */ key->eword--; } if (*set_ordering (s, key, bl_end)) badfieldspec (optarg1, N_("stray character in field spec")); } key->traditional_used = true; insertkey (key); } } } if (! key) files[nfiles++] = optarg; break; case SORT_OPTION: c = XARGMATCH ("--sort", optarg, sort_args, sort_types); FALLTHROUGH; case 'b': case 'd': case 'f': case 'g': case 'h': case 'i': case 'M': case 'n': case 'r': case 'R': case 'V': { char str[2]; str[0] = c; str[1] = '\0'; set_ordering (str, &gkey, bl_both); } break; case CHECK_OPTION: c = (optarg ? XARGMATCH ("--check", optarg, check_args, check_types) : 'c'); FALLTHROUGH; case 'c': case 'C': if (checkonly && checkonly != c) incompatible_options ("cC"); checkonly = c; break; case COMPRESS_PROGRAM_OPTION: if (compress_program && !STREQ (compress_program, optarg)) die (SORT_FAILURE, 0, _("multiple compress programs specified")); compress_program = optarg; break; case DEBUG_PROGRAM_OPTION: debug = true; break; case FILES0_FROM_OPTION: files_from = optarg; break; case 'k': key = key_init (&key_buf); /* Get POS1. */ s = parse_field_count (optarg, &key->sword, N_("invalid number at field start")); if (! key->sword--) { /* Provoke with 'sort -k0' */ badfieldspec (optarg, N_("field number is zero")); } if (*s == '.') { s = parse_field_count (s + 1, &key->schar, N_("invalid number after '.'")); if (! key->schar--) { /* Provoke with 'sort -k1.0' */ badfieldspec (optarg, N_("character offset is zero")); } } if (! (key->sword || key->schar)) key->sword = SIZE_MAX; s = set_ordering (s, key, bl_start); if (*s != ',') { key->eword = SIZE_MAX; key->echar = 0; } else { /* Get POS2. */ s = parse_field_count (s + 1, &key->eword, N_("invalid number after ','")); if (! key->eword--) { /* Provoke with 'sort -k1,0' */ badfieldspec (optarg, N_("field number is zero")); } if (*s == '.') { s = parse_field_count (s + 1, &key->echar, N_("invalid number after '.'")); } s = set_ordering (s, key, bl_end); } if (*s) badfieldspec (optarg, N_("stray character in field spec")); insertkey (key); break; case 'm': mergeonly = true; break; case NMERGE_OPTION: specify_nmerge (oi, c, optarg); break; case 'o': if (outfile && !STREQ (outfile, optarg)) die (SORT_FAILURE, 0, _("multiple output files specified")); outfile = optarg; break; case RANDOM_SOURCE_OPTION: if (random_source && !STREQ (random_source, optarg)) die (SORT_FAILURE, 0, _("multiple random sources specified")); random_source = optarg; break; case 's': stable = true; break; case 'S': specify_sort_size (oi, c, optarg); break; case 't': { char newtab = optarg[0]; if (! newtab) die (SORT_FAILURE, 0, _("empty tab")); if (optarg[1]) { if (STREQ (optarg, "\\0")) newtab = '\0'; else { /* Provoke with 'sort -txx'. Complain about "multi-character tab" instead of "multibyte tab", so that the diagnostic's wording does not need to be changed once multibyte characters are supported. */ die (SORT_FAILURE, 0, _("multi-character tab %s"), quote (optarg)); } } if (tab != TAB_DEFAULT && tab != newtab) die (SORT_FAILURE, 0, _("incompatible tabs")); tab = newtab; } break; case 'T': add_temp_dir (optarg); break; case PARALLEL_OPTION: nthreads = specify_nthreads (oi, c, optarg); break; case 'u': unique = true; break; case 'y': /* Accept and ignore e.g. -y0 for compatibility with Solaris 2.x through Solaris 7. It is also accepted by many non-Solaris "sort" implementations, e.g., AIX 5.2, HP-UX 11i v2, IRIX 6.5. -y is marked as obsolete starting with Solaris 8 (1999), but is still accepted as of Solaris 10 prerelease (2004). Solaris 2.5.1 "sort -y 100" reads the input file "100", but emulate Solaris 8 and 9 "sort -y 100" which ignores the "100", and which in general ignores the argument after "-y" if it consists entirely of digits (it can even be empty). */ if (optarg == argv[optind - 1]) { char const *p; for (p = optarg; ISDIGIT (*p); p++) continue; optind -= (*p != '\0'); } break; case 'z': eolchar = 0; break; case_GETOPT_HELP_CHAR; case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); default: usage (SORT_FAILURE); } } if (files_from) { /* When using --files0-from=F, you may not specify any files on the command-line. */ if (nfiles) { error (0, 0, _("extra operand %s"), quoteaf (files[0])); fprintf (stderr, "%s\n", _("file operands cannot be combined with --files0-from")); usage (SORT_FAILURE); } FILE *stream = xfopen (files_from, "r"); readtokens0_init (&tok); if (! readtokens0 (stream, &tok)) die (SORT_FAILURE, 0, _("cannot read file names from %s"), quoteaf (files_from)); xfclose (stream, files_from); if (tok.n_tok) { free (files); files = tok.tok; nfiles = tok.n_tok; for (size_t i = 0; i < nfiles; i++) { if (STREQ (files[i], "-")) die (SORT_FAILURE, 0, _("when reading file names from stdin, " "no file name of %s allowed"), quoteaf (files[i])); else if (files[i][0] == '\0') { /* Using the standard 'filename:line-number:' prefix here is not totally appropriate, since NUL is the separator, not NL, but it might be better than nothing. */ unsigned long int file_number = i + 1; die (SORT_FAILURE, 0, _("%s:%lu: invalid zero-length file name"), quotef (files_from), file_number); } } } else die (SORT_FAILURE, 0, _("no input from %s"), quoteaf (files_from)); } /* Inheritance of global options to individual keys. */ for (key = keylist; key; key = key->next) { if (default_key_compare (key) && !key->reverse) { key->ignore = gkey.ignore; key->translate = gkey.translate; key->skipsblanks = gkey.skipsblanks; key->skipeblanks = gkey.skipeblanks; key->month = gkey.month; key->numeric = gkey.numeric; key->general_numeric = gkey.general_numeric; key->human_numeric = gkey.human_numeric; key->version = gkey.version; key->random = gkey.random; key->reverse = gkey.reverse; } need_random |= key->random; } if (!keylist && !default_key_compare (&gkey)) { gkey_only = true; insertkey (&gkey); need_random |= gkey.random; } check_ordering_compatibility (); if (debug) { if (checkonly || outfile) { static char opts[] = "X --debug"; opts[0] = (checkonly ? checkonly : 'o'); incompatible_options (opts); } /* Always output the locale in debug mode, since this is such a common source of confusion. */ /* OpenBSD can only set some categories with LC_ALL above, so set LC_COLLATE explicitly to flag errors. */ if (locale_ok) locale_ok = !! setlocale (LC_COLLATE, ""); if (! locale_ok) error (0, 0, "%s", _("failed to set locale")); if (hard_LC_COLLATE) error (0, 0, _("text ordering performed using %s sorting rules"), quote (setlocale (LC_COLLATE, NULL))); else error (0, 0, "%s", _("text ordering performed using simple byte comparison")); key_warnings (&gkey, gkey_only); } reverse = gkey.reverse; if (need_random) random_md5_state_init (random_source); if (temp_dir_count == 0) { char const *tmp_dir = getenv ("TMPDIR"); add_temp_dir (tmp_dir ? tmp_dir : DEFAULT_TMPDIR); } if (nfiles == 0) { nfiles = 1; free (files); files = xmalloc (sizeof *files); *files = (char *) "-"; } /* Need to re-check that we meet the minimum requirement for memory usage with the final value for NMERGE. */ if (0 < sort_size) sort_size = MAX (sort_size, MIN_SORT_SIZE); if (checkonly) { if (nfiles > 1) die (SORT_FAILURE, 0, _("extra operand %s not allowed with -%c"), quoteaf (files[1]), checkonly); if (outfile) { static char opts[] = {0, 'o', 0}; opts[0] = checkonly; incompatible_options (opts); } /* POSIX requires that sort return 1 IFF invoked with -c or -C and the input is not properly sorted. */ return check (files[0], checkonly) ? EXIT_SUCCESS : SORT_OUT_OF_ORDER; } /* Check all inputs are accessible, or exit immediately. */ check_inputs (files, nfiles); /* Check output is writable, or exit immediately. */ check_output (outfile); if (mergeonly) { struct sortfile *sortfiles = xcalloc (nfiles, sizeof *sortfiles); for (size_t i = 0; i < nfiles; ++i) sortfiles[i].name = files[i]; merge (sortfiles, 0, nfiles, outfile); IF_LINT (free (sortfiles)); } else { if (!nthreads) { unsigned long int np = num_processors (NPROC_CURRENT_OVERRIDABLE); nthreads = MIN (np, DEFAULT_MAX_THREADS); } /* Avoid integer overflow later. */ size_t nthreads_max = SIZE_MAX / (2 * sizeof (struct merge_node)); nthreads = MIN (nthreads, nthreads_max); sort (files, nfiles, outfile, nthreads); } #ifdef lint if (files_from) readtokens0_free (&tok); else free (files); #endif if (have_read_stdin && fclose (stdin) == EOF) sort_die (_("close failed"), "-"); return EXIT_SUCCESS; }