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Diffstat (limited to 'src/paste.c')
| -rw-r--r-- | src/paste.c | 530 |
1 files changed, 530 insertions, 0 deletions
diff --git a/src/paste.c b/src/paste.c new file mode 100644 index 0000000..9f401c9 --- /dev/null +++ b/src/paste.c @@ -0,0 +1,530 @@ +/* paste - merge lines of files + Copyright (C) 1997-2020 Free Software Foundation, Inc. + Copyright (C) 1984 David M. Ihnat + + 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 <https://www.gnu.org/licenses/>. */ + +/* Written by David Ihnat. */ + +/* The list of valid escape sequences has been expanded over the Unix + version, to include \b, \f, \r, and \v. + + POSIX changes, bug fixes, long-named options, and cleanup + by David MacKenzie <djm@gnu.ai.mit.edu>. + + Options: + --serial + -s Paste one file at a time rather than + one line from each file. + --delimiters=delim-list + -d delim-list Consecutively use the characters in + DELIM-LIST instead of tab to separate + merged lines. When DELIM-LIST is exhausted, + start again at its beginning. + A FILE of '-' means standard input. + If no FILEs are given, standard input is used. */ + +#include <config.h> + +#include <stdio.h> +#include <getopt.h> +#include <sys/types.h> +#include "system.h" +#include "die.h" +#include "error.h" +#include "fadvise.h" + +/* The official name of this program (e.g., no 'g' prefix). */ +#define PROGRAM_NAME "paste" + +#define AUTHORS \ + proper_name ("David M. Ihnat"), \ + proper_name ("David MacKenzie") + +/* Indicates that no delimiter should be added in the current position. */ +#define EMPTY_DELIM '\0' + +/* If nonzero, we have read standard input at some point. */ +static bool have_read_stdin; + +/* If nonzero, merge subsequent lines of each file rather than + corresponding lines from each file in parallel. */ +static bool serial_merge; + +/* The delimiters between lines of input files (used cyclically). */ +static char *delims; + +/* A pointer to the character after the end of 'delims'. */ +static char const *delim_end; + +static unsigned char line_delim = '\n'; + +static struct option const longopts[] = +{ + {"serial", no_argument, NULL, 's'}, + {"delimiters", required_argument, NULL, 'd'}, + {"zero-terminated", no_argument, NULL, 'z'}, + {GETOPT_HELP_OPTION_DECL}, + {GETOPT_VERSION_OPTION_DECL}, + {NULL, 0, NULL, 0} +}; + +/* Set globals delims and delim_end. Copy STRPTR to DELIMS, converting + backslash representations of special characters in STRPTR to their actual + values. The set of possible backslash characters has been expanded beyond + that recognized by the Unix version. + Return 0 upon success. + If the string ends in an odd number of backslashes, ignore the + final backslash and return nonzero. */ + +static int +collapse_escapes (char const *strptr) +{ + char *strout = xstrdup (strptr); + bool backslash_at_end = false; + + delims = strout; + + while (*strptr) + { + if (*strptr != '\\') /* Is it an escape character? */ + *strout++ = *strptr++; /* No, just transfer it. */ + else + { + switch (*++strptr) + { + case '0': + *strout++ = EMPTY_DELIM; + break; + + case 'b': + *strout++ = '\b'; + break; + + case 'f': + *strout++ = '\f'; + break; + + case 'n': + *strout++ = '\n'; + break; + + case 'r': + *strout++ = '\r'; + break; + + case 't': + *strout++ = '\t'; + break; + + case 'v': + *strout++ = '\v'; + break; + + case '\\': + *strout++ = '\\'; + break; + + case '\0': + backslash_at_end = true; + goto done; + + default: + *strout++ = *strptr; + break; + } + strptr++; + } + } + + done: + + delim_end = strout; + return backslash_at_end ? 1 : 0; +} + +/* Report a write error and exit. */ + +static void write_error (void) ATTRIBUTE_NORETURN; +static void +write_error (void) +{ + die (EXIT_FAILURE, errno, _("write error")); +} + +/* Output a single byte, reporting any write errors. */ + +static inline void +xputchar (char c) +{ + if (putchar (c) < 0) + write_error (); +} + +/* Perform column paste on the NFILES files named in FNAMPTR. + Return true if successful, false if one or more files could not be + opened or read. */ + +static bool +paste_parallel (size_t nfiles, char **fnamptr) +{ + bool ok = true; + /* If all files are just ready to be closed, or will be on this + round, the string of delimiters must be preserved. + delbuf[0] through delbuf[nfiles] + store the delimiters for closed files. */ + char *delbuf = xmalloc (nfiles + 2); + + /* Streams open to the files to process; NULL if the corresponding + stream is closed. */ + FILE **fileptr = xnmalloc (nfiles + 1, sizeof *fileptr); + + /* Number of files still open to process. */ + size_t files_open; + + /* True if any fopen got fd == STDIN_FILENO. */ + bool opened_stdin = false; + + /* Attempt to open all files. This could be expanded to an infinite + number of files, but at the (considerable) expense of remembering + each file and its current offset, then opening/reading/closing. */ + + for (files_open = 0; files_open < nfiles; ++files_open) + { + if (STREQ (fnamptr[files_open], "-")) + { + have_read_stdin = true; + fileptr[files_open] = stdin; + } + else + { + fileptr[files_open] = fopen (fnamptr[files_open], "r"); + if (fileptr[files_open] == NULL) + die (EXIT_FAILURE, errno, "%s", quotef (fnamptr[files_open])); + else if (fileno (fileptr[files_open]) == STDIN_FILENO) + opened_stdin = true; + fadvise (fileptr[files_open], FADVISE_SEQUENTIAL); + } + } + + if (opened_stdin && have_read_stdin) + die (EXIT_FAILURE, 0, _("standard input is closed")); + + /* Read a line from each file and output it to stdout separated by a + delimiter, until we go through the loop without successfully + reading from any of the files. */ + + while (files_open) + { + /* Set up for the next line. */ + bool somedone = false; + char const *delimptr = delims; + size_t delims_saved = 0; /* Number of delims saved in 'delbuf'. */ + + for (size_t i = 0; i < nfiles && files_open; i++) + { + int chr IF_LINT ( = 0); /* Input character. */ + int err IF_LINT ( = 0); /* Input errno value. */ + bool sometodo = false; /* Input chars to process. */ + + if (fileptr[i]) + { + chr = getc (fileptr[i]); + err = errno; + if (chr != EOF && delims_saved) + { + if (fwrite (delbuf, 1, delims_saved, stdout) != delims_saved) + write_error (); + delims_saved = 0; + } + + while (chr != EOF) + { + sometodo = true; + if (chr == line_delim) + break; + xputchar (chr); + chr = getc (fileptr[i]); + err = errno; + } + } + + if (! sometodo) + { + /* EOF, read error, or closed file. + If an EOF or error, close the file. */ + if (fileptr[i]) + { + if (ferror (fileptr[i])) + { + error (0, err, "%s", quotef (fnamptr[i])); + ok = false; + } + if (fileptr[i] == stdin) + clearerr (fileptr[i]); /* Also clear EOF. */ + else if (fclose (fileptr[i]) == EOF) + { + error (0, errno, "%s", quotef (fnamptr[i])); + ok = false; + } + + fileptr[i] = NULL; + files_open--; + } + + if (i + 1 == nfiles) + { + /* End of this output line. + Is this the end of the whole thing? */ + if (somedone) + { + /* No. Some files were not closed for this line. */ + if (delims_saved) + { + if (fwrite (delbuf, 1, delims_saved, stdout) + != delims_saved) + write_error (); + delims_saved = 0; + } + xputchar (line_delim); + } + continue; /* Next read of files, or exit. */ + } + else + { + /* Closed file; add delimiter to 'delbuf'. */ + if (*delimptr != EMPTY_DELIM) + delbuf[delims_saved++] = *delimptr; + if (++delimptr == delim_end) + delimptr = delims; + } + } + else + { + /* Some data read. */ + somedone = true; + + /* Except for last file, replace last newline with delim. */ + if (i + 1 != nfiles) + { + if (chr != line_delim && chr != EOF) + xputchar (chr); + if (*delimptr != EMPTY_DELIM) + xputchar (*delimptr); + if (++delimptr == delim_end) + delimptr = delims; + } + else + { + /* If the last line of the last file lacks a newline, + print one anyhow. POSIX requires this. */ + char c = (chr == EOF ? line_delim : chr); + xputchar (c); + } + } + } + } + free (fileptr); + free (delbuf); + return ok; +} + +/* Perform serial paste on the NFILES files named in FNAMPTR. + Return true if no errors, false if one or more files could not be + opened or read. */ + +static bool +paste_serial (size_t nfiles, char **fnamptr) +{ + bool ok = true; /* false if open or read errors occur. */ + int charnew, charold; /* Current and previous char read. */ + char const *delimptr; /* Current delimiter char. */ + FILE *fileptr; /* Open for reading current file. */ + + for (; nfiles; nfiles--, fnamptr++) + { + int saved_errno; + bool is_stdin = STREQ (*fnamptr, "-"); + if (is_stdin) + { + have_read_stdin = true; + fileptr = stdin; + } + else + { + fileptr = fopen (*fnamptr, "r"); + if (fileptr == NULL) + { + error (0, errno, "%s", quotef (*fnamptr)); + ok = false; + continue; + } + fadvise (fileptr, FADVISE_SEQUENTIAL); + } + + delimptr = delims; /* Set up for delimiter string. */ + + charold = getc (fileptr); + saved_errno = errno; + if (charold != EOF) + { + /* 'charold' is set up. Hit it! + Keep reading characters, stashing them in 'charnew'; + output 'charold', converting to the appropriate delimiter + character if needed. After the EOF, output 'charold' + if it's a newline; otherwise, output it and then a newline. */ + + while ((charnew = getc (fileptr)) != EOF) + { + /* Process the old character. */ + if (charold == line_delim) + { + if (*delimptr != EMPTY_DELIM) + xputchar (*delimptr); + + if (++delimptr == delim_end) + delimptr = delims; + } + else + xputchar (charold); + + charold = charnew; + } + saved_errno = errno; + + /* Hit EOF. Process that last character. */ + xputchar (charold); + } + + if (charold != line_delim) + xputchar (line_delim); + + if (ferror (fileptr)) + { + error (0, saved_errno, "%s", quotef (*fnamptr)); + ok = false; + } + if (is_stdin) + clearerr (fileptr); /* Also clear EOF. */ + else if (fclose (fileptr) == EOF) + { + error (0, errno, "%s", quotef (*fnamptr)); + ok = false; + } + } + return ok; +} + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + emit_try_help (); + else + { + printf (_("\ +Usage: %s [OPTION]... [FILE]...\n\ +"), + program_name); + fputs (_("\ +Write lines consisting of the sequentially corresponding lines from\n\ +each FILE, separated by TABs, to standard output.\n\ +"), stdout); + + emit_stdin_note (); + emit_mandatory_arg_note (); + + fputs (_("\ + -d, --delimiters=LIST reuse characters from LIST instead of TABs\n\ + -s, --serial paste one file at a time instead of in parallel\n\ +"), stdout); + fputs (_("\ + -z, --zero-terminated line delimiter is NUL, not newline\n\ +"), stdout); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + /* FIXME: add a couple of examples. */ + emit_ancillary_info (PROGRAM_NAME); + } + exit (status); +} + +int +main (int argc, char **argv) +{ + int optc; + char const *delim_arg = "\t"; + + initialize_main (&argc, &argv); + set_program_name (argv[0]); + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + atexit (close_stdout); + + have_read_stdin = false; + serial_merge = false; + + while ((optc = getopt_long (argc, argv, "d:sz", longopts, NULL)) != -1) + { + switch (optc) + { + case 'd': + /* Delimiter character(s). */ + delim_arg = (optarg[0] == '\0' ? "\\0" : optarg); + break; + + case 's': + serial_merge = true; + break; + + case 'z': + line_delim = '\0'; + break; + + case_GETOPT_HELP_CHAR; + + case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); + + default: + usage (EXIT_FAILURE); + } + } + + int nfiles = argc - optind; + if (nfiles == 0) + { + argv[optind] = bad_cast ("-"); + nfiles++; + } + + if (collapse_escapes (delim_arg)) + { + /* Don't use the quote() quoting style, because that would double the + number of displayed backslashes, making the diagnostic look bogus. */ + die (EXIT_FAILURE, 0, + _("delimiter list ends with an unescaped backslash: %s"), + quotearg_n_style_colon (0, c_maybe_quoting_style, delim_arg)); + } + + bool ok = ((serial_merge ? paste_serial : paste_parallel) + (nfiles, &argv[optind])); + + free (delims); + + if (have_read_stdin && fclose (stdin) == EOF) + die (EXIT_FAILURE, errno, "-"); + return ok ? EXIT_SUCCESS : EXIT_FAILURE; +} |