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Diffstat (limited to 'general.c')
| -rw-r--r-- | general.c | 1441 |
1 files changed, 1441 insertions, 0 deletions
diff --git a/general.c b/general.c new file mode 100644 index 0000000..50d5216 --- /dev/null +++ b/general.c @@ -0,0 +1,1441 @@ +/* general.c -- Stuff that is used by all files. */ + +/* Copyright (C) 1987-2020 Free Software Foundation, Inc. + + This file is part of GNU Bash, the Bourne Again SHell. + + Bash 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. + + Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "config.h" + +#include "bashtypes.h" +#if defined (HAVE_SYS_PARAM_H) +# include <sys/param.h> +#endif +#include "posixstat.h" + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include "filecntl.h" +#include "bashansi.h" +#include <stdio.h> +#include "chartypes.h" +#include <errno.h> + +#include "bashintl.h" + +#include "shell.h" +#include "parser.h" +#include "flags.h" +#include "findcmd.h" +#include "test.h" +#include "trap.h" +#include "pathexp.h" + +#include "builtins/common.h" + +#if defined (HAVE_MBSTR_H) && defined (HAVE_MBSCHR) +# include <mbstr.h> /* mbschr */ +#endif + +#include <tilde/tilde.h> + +#if !defined (errno) +extern int errno; +#endif /* !errno */ + +#ifdef __CYGWIN__ +# include <sys/cygwin.h> +#endif + +static char *bash_special_tilde_expansions PARAMS((char *)); +static int unquoted_tilde_word PARAMS((const char *)); +static void initialize_group_array PARAMS((void)); + +/* A standard error message to use when getcwd() returns NULL. */ +const char * const bash_getcwd_errstr = N_("getcwd: cannot access parent directories"); + +/* Do whatever is necessary to initialize `Posix mode'. This currently + modifies the following variables which are controlled via shopt: + interactive_comments + source_uses_path + expand_aliases + inherit_errexit + print_shift_error + posixglob + + and the following variables which cannot be user-modified: + + source_searches_cwd + + If we add to the first list, we need to change the table and functions + below */ + +static struct { + int *posix_mode_var; +} posix_vars[] = +{ + &interactive_comments, + &source_uses_path, + &expand_aliases, + &inherit_errexit, + &print_shift_error, + 0 +}; + +static char *saved_posix_vars = 0; + +void +posix_initialize (on) + int on; +{ + /* Things that should be turned on when posix mode is enabled. */ + if (on != 0) + { + interactive_comments = source_uses_path = expand_aliases = 1; + inherit_errexit = 1; + source_searches_cwd = 0; + print_shift_error = 1; + } + + /* Things that should be turned on when posix mode is disabled. */ + else if (saved_posix_vars) /* on == 0, restore saved settings */ + { + set_posix_options (saved_posix_vars); + free (saved_posix_vars); + saved_posix_vars = 0; + } + else /* on == 0, restore a default set of settings */ + { + source_searches_cwd = 1; + expand_aliases = interactive_shell; + print_shift_error = 0; + } +} + +int +num_posix_options () +{ + return ((sizeof (posix_vars) / sizeof (posix_vars[0])) - 1); +} + +char * +get_posix_options (bitmap) + char *bitmap; +{ + register int i; + + if (bitmap == 0) + bitmap = (char *)xmalloc (num_posix_options ()); /* no trailing NULL */ + for (i = 0; posix_vars[i].posix_mode_var; i++) + bitmap[i] = *(posix_vars[i].posix_mode_var); + return bitmap; +} + +#undef save_posix_options +void +save_posix_options () +{ + saved_posix_vars = get_posix_options (saved_posix_vars); +} + +void +set_posix_options (bitmap) + const char *bitmap; +{ + register int i; + + for (i = 0; posix_vars[i].posix_mode_var; i++) + *(posix_vars[i].posix_mode_var) = bitmap[i]; +} + +/* **************************************************************** */ +/* */ +/* Functions to convert to and from and display non-standard types */ +/* */ +/* **************************************************************** */ + +#if defined (RLIMTYPE) +RLIMTYPE +string_to_rlimtype (s) + char *s; +{ + RLIMTYPE ret; + int neg; + + ret = 0; + neg = 0; + while (s && *s && whitespace (*s)) + s++; + if (s && (*s == '-' || *s == '+')) + { + neg = *s == '-'; + s++; + } + for ( ; s && *s && DIGIT (*s); s++) + ret = (ret * 10) + TODIGIT (*s); + return (neg ? -ret : ret); +} + +void +print_rlimtype (n, addnl) + RLIMTYPE n; + int addnl; +{ + char s[INT_STRLEN_BOUND (RLIMTYPE) + 1], *p; + + p = s + sizeof(s); + *--p = '\0'; + + if (n < 0) + { + do + *--p = '0' - n % 10; + while ((n /= 10) != 0); + + *--p = '-'; + } + else + { + do + *--p = '0' + n % 10; + while ((n /= 10) != 0); + } + + printf ("%s%s", p, addnl ? "\n" : ""); +} +#endif /* RLIMTYPE */ + +/* **************************************************************** */ +/* */ +/* Input Validation Functions */ +/* */ +/* **************************************************************** */ + +/* Return non-zero if all of the characters in STRING are digits. */ +int +all_digits (string) + const char *string; +{ + register const char *s; + + for (s = string; *s; s++) + if (DIGIT (*s) == 0) + return (0); + + return (1); +} + +/* Return non-zero if the characters pointed to by STRING constitute a + valid number. Stuff the converted number into RESULT if RESULT is + not null. */ +int +legal_number (string, result) + const char *string; + intmax_t *result; +{ + intmax_t value; + char *ep; + + if (result) + *result = 0; + + if (string == 0) + return 0; + + errno = 0; + value = strtoimax (string, &ep, 10); + if (errno || ep == string) + return 0; /* errno is set on overflow or underflow */ + + /* Skip any trailing whitespace, since strtoimax does not. */ + while (whitespace (*ep)) + ep++; + + /* If *string is not '\0' but *ep is '\0' on return, the entire string + is valid. */ + if (*string && *ep == '\0') + { + if (result) + *result = value; + /* The SunOS4 implementation of strtol() will happily ignore + overflow conditions, so this cannot do overflow correctly + on those systems. */ + return 1; + } + + return (0); +} + +/* Return 1 if this token is a legal shell `identifier'; that is, it consists + solely of letters, digits, and underscores, and does not begin with a + digit. */ +int +legal_identifier (name) + const char *name; +{ + register const char *s; + unsigned char c; + + if (!name || !(c = *name) || (legal_variable_starter (c) == 0)) + return (0); + + for (s = name + 1; (c = *s) != 0; s++) + { + if (legal_variable_char (c) == 0) + return (0); + } + return (1); +} + +/* Return 1 if NAME is a valid value that can be assigned to a nameref + variable. FLAGS can be 2, in which case the name is going to be used + to create a variable. Other values are currently unused, but could + be used to allow values to be stored and indirectly referenced, but + not used in assignments. */ +int +valid_nameref_value (name, flags) + const char *name; + int flags; +{ + if (name == 0 || *name == 0) + return 0; + + /* valid identifier */ +#if defined (ARRAY_VARS) + if (legal_identifier (name) || (flags != 2 && valid_array_reference (name, 0))) +#else + if (legal_identifier (name)) +#endif + return 1; + + return 0; +} + +int +check_selfref (name, value, flags) + const char *name; + char *value; + int flags; +{ + char *t; + + if (STREQ (name, value)) + return 1; + +#if defined (ARRAY_VARS) + if (valid_array_reference (value, 0)) + { + t = array_variable_name (value, 0, (char **)NULL, (int *)NULL); + if (t && STREQ (name, t)) + { + free (t); + return 1; + } + free (t); + } +#endif + + return 0; /* not a self reference */ +} + +/* Make sure that WORD is a valid shell identifier, i.e. + does not contain a dollar sign, nor is quoted in any way. + If CHECK_WORD is non-zero, + the word is checked to ensure that it consists of only letters, + digits, and underscores, and does not consist of all digits. */ +int +check_identifier (word, check_word) + WORD_DESC *word; + int check_word; +{ + if (word->flags & (W_HASDOLLAR|W_QUOTED)) /* XXX - HASDOLLAR? */ + { + internal_error (_("`%s': not a valid identifier"), word->word); + return (0); + } + else if (check_word && (all_digits (word->word) || legal_identifier (word->word) == 0)) + { + internal_error (_("`%s': not a valid identifier"), word->word); + return (0); + } + else + return (1); +} + +/* Return 1 if STRING is a function name that the shell will import from + the environment. Currently we reject attempts to import shell functions + containing slashes, beginning with newlines or containing blanks. In + Posix mode, we require that STRING be a valid shell identifier. Not + used yet. */ +int +importable_function_name (string, len) + const char *string; + size_t len; +{ + if (absolute_program (string)) /* don't allow slash */ + return 0; + if (*string == '\n') /* can't start with a newline */ + return 0; + if (shellblank (*string) || shellblank(string[len-1])) + return 0; + return (posixly_correct ? legal_identifier (string) : 1); +} + +int +exportable_function_name (string) + const char *string; +{ + if (absolute_program (string)) + return 0; + if (mbschr (string, '=') != 0) + return 0; + return 1; +} + +/* Return 1 if STRING comprises a valid alias name. The shell accepts + essentially all characters except those which must be quoted to the + parser (which disqualifies them from alias expansion anyway) and `/'. */ +int +legal_alias_name (string, flags) + const char *string; + int flags; +{ + register const char *s; + + for (s = string; *s; s++) + if (shellbreak (*s) || shellxquote (*s) || shellexp (*s) || (*s == '/')) + return 0; + return 1; +} + +/* Returns non-zero if STRING is an assignment statement. The returned value + is the index of the `=' sign. If FLAGS&1 we are expecting a compound assignment + and require an array subscript before the `=' to denote an assignment + statement. */ +int +assignment (string, flags) + const char *string; + int flags; +{ + register unsigned char c; + register int newi, indx; + + c = string[indx = 0]; + +#if defined (ARRAY_VARS) + /* If parser_state includes PST_COMPASSIGN, FLAGS will include 1, so we are + parsing the contents of a compound assignment. If parser_state includes + PST_REPARSE, we are in the middle of an assignment statement and breaking + the words between the parens into words and assignment statements, but + we don't need to check for that right now. Within a compound assignment, + the subscript is required to make the word an assignment statement. If + we don't have a subscript, even if the word is a valid assignment + statement otherwise, we don't want to treat it as one. */ + if ((flags & 1) && c != '[') /* ] */ + return (0); + else if ((flags & 1) == 0 && legal_variable_starter (c) == 0) +#else + if (legal_variable_starter (c) == 0) +#endif + return (0); + + while (c = string[indx]) + { + /* The following is safe. Note that '=' at the start of a word + is not an assignment statement. */ + if (c == '=') + return (indx); + +#if defined (ARRAY_VARS) + if (c == '[') + { + newi = skipsubscript (string, indx, (flags & 2) ? 1 : 0); + /* XXX - why not check for blank subscripts here, if we do in + valid_array_reference? */ + if (string[newi++] != ']') + return (0); + if (string[newi] == '+' && string[newi+1] == '=') + return (newi + 1); + return ((string[newi] == '=') ? newi : 0); + } +#endif /* ARRAY_VARS */ + + /* Check for `+=' */ + if (c == '+' && string[indx+1] == '=') + return (indx + 1); + + /* Variable names in assignment statements may contain only letters, + digits, and `_'. */ + if (legal_variable_char (c) == 0) + return (0); + + indx++; + } + return (0); +} + +int +line_isblank (line) + const char *line; +{ + register int i; + + if (line == 0) + return 0; /* XXX */ + for (i = 0; line[i]; i++) + if (isblank ((unsigned char)line[i]) == 0) + break; + return (line[i] == '\0'); +} + +/* **************************************************************** */ +/* */ +/* Functions to manage files and file descriptors */ +/* */ +/* **************************************************************** */ + +/* A function to unset no-delay mode on a file descriptor. Used in shell.c + to unset it on the fd passed as stdin. Should be called on stdin if + readline gets an EAGAIN or EWOULDBLOCK when trying to read input. */ + +#if !defined (O_NDELAY) +# if defined (FNDELAY) +# define O_NDELAY FNDELAY +# endif +#endif /* O_NDELAY */ + +/* Make sure no-delay mode is not set on file descriptor FD. */ +int +sh_unset_nodelay_mode (fd) + int fd; +{ + int flags, bflags; + + if ((flags = fcntl (fd, F_GETFL, 0)) < 0) + return -1; + + bflags = 0; + + /* This is defined to O_NDELAY in filecntl.h if O_NONBLOCK is not present + and O_NDELAY is defined. */ +#ifdef O_NONBLOCK + bflags |= O_NONBLOCK; +#endif + +#ifdef O_NDELAY + bflags |= O_NDELAY; +#endif + + if (flags & bflags) + { + flags &= ~bflags; + return (fcntl (fd, F_SETFL, flags)); + } + + return 0; +} + +/* Just a wrapper for the define in include/filecntl.h */ +int +sh_setclexec (fd) + int fd; +{ + return (SET_CLOSE_ON_EXEC (fd)); +} + +/* Return 1 if file descriptor FD is valid; 0 otherwise. */ +int +sh_validfd (fd) + int fd; +{ + return (fcntl (fd, F_GETFD, 0) >= 0); +} + +int +fd_ispipe (fd) + int fd; +{ + errno = 0; + return ((lseek (fd, 0L, SEEK_CUR) < 0) && (errno == ESPIPE)); +} + +/* There is a bug in the NeXT 2.1 rlogind that causes opens + of /dev/tty to fail. */ + +#if defined (__BEOS__) +/* On BeOS, opening in non-blocking mode exposes a bug in BeOS, so turn it + into a no-op. This should probably go away in the future. */ +# undef O_NONBLOCK +# define O_NONBLOCK 0 +#endif /* __BEOS__ */ + +void +check_dev_tty () +{ + int tty_fd; + char *tty; + + tty_fd = open ("/dev/tty", O_RDWR|O_NONBLOCK); + + if (tty_fd < 0) + { + tty = (char *)ttyname (fileno (stdin)); + if (tty == 0) + return; + tty_fd = open (tty, O_RDWR|O_NONBLOCK); + } + if (tty_fd >= 0) + close (tty_fd); +} + +/* Return 1 if PATH1 and PATH2 are the same file. This is kind of + expensive. If non-NULL STP1 and STP2 point to stat structures + corresponding to PATH1 and PATH2, respectively. */ +int +same_file (path1, path2, stp1, stp2) + const char *path1, *path2; + struct stat *stp1, *stp2; +{ + struct stat st1, st2; + + if (stp1 == NULL) + { + if (stat (path1, &st1) != 0) + return (0); + stp1 = &st1; + } + + if (stp2 == NULL) + { + if (stat (path2, &st2) != 0) + return (0); + stp2 = &st2; + } + + return ((stp1->st_dev == stp2->st_dev) && (stp1->st_ino == stp2->st_ino)); +} + +/* Move FD to a number close to the maximum number of file descriptors + allowed in the shell process, to avoid the user stepping on it with + redirection and causing us extra work. If CHECK_NEW is non-zero, + we check whether or not the file descriptors are in use before + duplicating FD onto them. MAXFD says where to start checking the + file descriptors. If it's less than 20, we get the maximum value + available from getdtablesize(2). */ +int +move_to_high_fd (fd, check_new, maxfd) + int fd, check_new, maxfd; +{ + int script_fd, nfds, ignore; + + if (maxfd < 20) + { + nfds = getdtablesize (); + if (nfds <= 0) + nfds = 20; + if (nfds > HIGH_FD_MAX) + nfds = HIGH_FD_MAX; /* reasonable maximum */ + } + else + nfds = maxfd; + + for (nfds--; check_new && nfds > 3; nfds--) + if (fcntl (nfds, F_GETFD, &ignore) == -1) + break; + + if (nfds > 3 && fd != nfds && (script_fd = dup2 (fd, nfds)) != -1) + { + if (check_new == 0 || fd != fileno (stderr)) /* don't close stderr */ + close (fd); + return (script_fd); + } + + /* OK, we didn't find one less than our artificial maximum; return the + original file descriptor. */ + return (fd); +} + +/* Return non-zero if the characters from SAMPLE are not all valid + characters to be found in the first line of a shell script. We + check up to the first newline, or SAMPLE_LEN, whichever comes first. + All of the characters must be printable or whitespace. */ + +int +check_binary_file (sample, sample_len) + const char *sample; + int sample_len; +{ + register int i; + unsigned char c; + + for (i = 0; i < sample_len; i++) + { + c = sample[i]; + if (c == '\n') + return (0); + if (c == '\0') + return (1); + } + + return (0); +} + +/* **************************************************************** */ +/* */ +/* Functions to manipulate pipes */ +/* */ +/* **************************************************************** */ + +int +sh_openpipe (pv) + int *pv; +{ + int r; + + if ((r = pipe (pv)) < 0) + return r; + + pv[0] = move_to_high_fd (pv[0], 1, 64); + pv[1] = move_to_high_fd (pv[1], 1, 64); + + return 0; +} + +int +sh_closepipe (pv) + int *pv; +{ + if (pv[0] >= 0) + close (pv[0]); + + if (pv[1] >= 0) + close (pv[1]); + + pv[0] = pv[1] = -1; + return 0; +} + +/* **************************************************************** */ +/* */ +/* Functions to inspect pathnames */ +/* */ +/* **************************************************************** */ + +int +file_exists (fn) + const char *fn; +{ + struct stat sb; + + return (stat (fn, &sb) == 0); +} + +int +file_isdir (fn) + const char *fn; +{ + struct stat sb; + + return ((stat (fn, &sb) == 0) && S_ISDIR (sb.st_mode)); +} + +int +file_iswdir (fn) + const char *fn; +{ + return (file_isdir (fn) && sh_eaccess (fn, W_OK) == 0); +} + +/* Return 1 if STRING is "." or "..", optionally followed by a directory + separator */ +int +path_dot_or_dotdot (string) + const char *string; +{ + if (string == 0 || *string == '\0' || *string != '.') + return (0); + + /* string[0] == '.' */ + if (PATHSEP(string[1]) || (string[1] == '.' && PATHSEP(string[2]))) + return (1); + + return (0); +} + +/* Return 1 if STRING contains an absolute pathname, else 0. Used by `cd' + to decide whether or not to look up a directory name in $CDPATH. */ +int +absolute_pathname (string) + const char *string; +{ + if (string == 0 || *string == '\0') + return (0); + + if (ABSPATH(string)) + return (1); + + if (string[0] == '.' && PATHSEP(string[1])) /* . and ./ */ + return (1); + + if (string[0] == '.' && string[1] == '.' && PATHSEP(string[2])) /* .. and ../ */ + return (1); + + return (0); +} + +/* Return 1 if STRING is an absolute program name; it is absolute if it + contains any slashes. This is used to decide whether or not to look + up through $PATH. */ +int +absolute_program (string) + const char *string; +{ + return ((char *)mbschr (string, '/') != (char *)NULL); +} + +/* **************************************************************** */ +/* */ +/* Functions to manipulate pathnames */ +/* */ +/* **************************************************************** */ + +/* Turn STRING (a pathname) into an absolute pathname, assuming that + DOT_PATH contains the symbolic location of `.'. This always + returns a new string, even if STRING was an absolute pathname to + begin with. */ +char * +make_absolute (string, dot_path) + const char *string, *dot_path; +{ + char *result; + + if (dot_path == 0 || ABSPATH(string)) +#ifdef __CYGWIN__ + { + char pathbuf[PATH_MAX + 1]; + + /* WAS cygwin_conv_to_full_posix_path (string, pathbuf); */ + cygwin_conv_path (CCP_WIN_A_TO_POSIX, string, pathbuf, PATH_MAX); + result = savestring (pathbuf); + } +#else + result = savestring (string); +#endif + else + result = sh_makepath (dot_path, string, 0); + + return (result); +} + +/* Return the `basename' of the pathname in STRING (the stuff after the + last '/'). If STRING is `/', just return it. */ +char * +base_pathname (string) + char *string; +{ + char *p; + +#if 0 + if (absolute_pathname (string) == 0) + return (string); +#endif + + if (string[0] == '/' && string[1] == 0) + return (string); + + p = (char *)strrchr (string, '/'); + return (p ? ++p : string); +} + +/* Return the full pathname of FILE. Easy. Filenames that begin + with a '/' are returned as themselves. Other filenames have + the current working directory prepended. A new string is + returned in either case. */ +char * +full_pathname (file) + char *file; +{ + char *ret; + + file = (*file == '~') ? bash_tilde_expand (file, 0) : savestring (file); + + if (ABSPATH(file)) + return (file); + + ret = sh_makepath ((char *)NULL, file, (MP_DOCWD|MP_RMDOT)); + free (file); + + return (ret); +} + +/* A slightly related function. Get the prettiest name of this + directory possible. */ +static char tdir[PATH_MAX]; + +/* Return a pretty pathname. If the first part of the pathname is + the same as $HOME, then replace that with `~'. */ +char * +polite_directory_format (name) + char *name; +{ + char *home; + int l; + + home = get_string_value ("HOME"); + l = home ? strlen (home) : 0; + if (l > 1 && strncmp (home, name, l) == 0 && (!name[l] || name[l] == '/')) + { + strncpy (tdir + 1, name + l, sizeof(tdir) - 2); + tdir[0] = '~'; + tdir[sizeof(tdir) - 1] = '\0'; + return (tdir); + } + else + return (name); +} + +/* Trim NAME. If NAME begins with `~/', skip over tilde prefix. Trim to + keep any tilde prefix and PROMPT_DIRTRIM trailing directory components + and replace the intervening characters with `...' */ +char * +trim_pathname (name, maxlen) + char *name; + int maxlen; +{ + int nlen, ndirs; + intmax_t nskip; + char *nbeg, *nend, *ntail, *v; + + if (name == 0 || (nlen = strlen (name)) == 0) + return name; + nend = name + nlen; + + v = get_string_value ("PROMPT_DIRTRIM"); + if (v == 0 || *v == 0) + return name; + if (legal_number (v, &nskip) == 0 || nskip <= 0) + return name; + + /* Skip over tilde prefix */ + nbeg = name; + if (name[0] == '~') + for (nbeg = name; *nbeg; nbeg++) + if (*nbeg == '/') + { + nbeg++; + break; + } + if (*nbeg == 0) + return name; + + for (ndirs = 0, ntail = nbeg; *ntail; ntail++) + if (*ntail == '/') + ndirs++; + if (ndirs < nskip) + return name; + + for (ntail = (*nend == '/') ? nend : nend - 1; ntail > nbeg; ntail--) + { + if (*ntail == '/') + nskip--; + if (nskip == 0) + break; + } + if (ntail == nbeg) + return name; + + /* Now we want to return name[0..nbeg]+"..."+ntail, modifying name in place */ + nlen = ntail - nbeg; + if (nlen <= 3) + return name; + + *nbeg++ = '.'; + *nbeg++ = '.'; + *nbeg++ = '.'; + + nlen = nend - ntail; + memmove (nbeg, ntail, nlen); + nbeg[nlen] = '\0'; + + return name; +} + +/* Return a printable representation of FN without special characters. The + caller is responsible for freeing memory if this returns something other + than its argument. If FLAGS is non-zero, we are printing for portable + re-input and should single-quote filenames appropriately. */ +char * +printable_filename (fn, flags) + char *fn; + int flags; +{ + char *newf; + + if (ansic_shouldquote (fn)) + newf = ansic_quote (fn, 0, NULL); + else if (flags && sh_contains_shell_metas (fn)) + newf = sh_single_quote (fn); + else + newf = fn; + + return newf; +} + +/* Given a string containing units of information separated by colons, + return the next one pointed to by (P_INDEX), or NULL if there are no more. + Advance (P_INDEX) to the character after the colon. */ +char * +extract_colon_unit (string, p_index) + char *string; + int *p_index; +{ + int i, start, len; + char *value; + + if (string == 0) + return (string); + + len = strlen (string); + if (*p_index >= len) + return ((char *)NULL); + + i = *p_index; + + /* Each call to this routine leaves the index pointing at a colon if + there is more to the path. If I is > 0, then increment past the + `:'. If I is 0, then the path has a leading colon. Trailing colons + are handled OK by the `else' part of the if statement; an empty + string is returned in that case. */ + if (i && string[i] == ':') + i++; + + for (start = i; string[i] && string[i] != ':'; i++) + ; + + *p_index = i; + + if (i == start) + { + if (string[i]) + (*p_index)++; + /* Return "" in the case of a trailing `:'. */ + value = (char *)xmalloc (1); + value[0] = '\0'; + } + else + value = substring (string, start, i); + + return (value); +} + +/* **************************************************************** */ +/* */ +/* Tilde Initialization and Expansion */ +/* */ +/* **************************************************************** */ + +#if defined (PUSHD_AND_POPD) +extern char *get_dirstack_from_string PARAMS((char *)); +#endif + +static char **bash_tilde_prefixes; +static char **bash_tilde_prefixes2; +static char **bash_tilde_suffixes; +static char **bash_tilde_suffixes2; + +/* If tilde_expand hasn't been able to expand the text, perhaps it + is a special shell expansion. This function is installed as the + tilde_expansion_preexpansion_hook. It knows how to expand ~- and ~+. + If PUSHD_AND_POPD is defined, ~[+-]N expands to directories from the + directory stack. */ +static char * +bash_special_tilde_expansions (text) + char *text; +{ + char *result; + + result = (char *)NULL; + + if (text[0] == '+' && text[1] == '\0') + result = get_string_value ("PWD"); + else if (text[0] == '-' && text[1] == '\0') + result = get_string_value ("OLDPWD"); +#if defined (PUSHD_AND_POPD) + else if (DIGIT (*text) || ((*text == '+' || *text == '-') && DIGIT (text[1]))) + result = get_dirstack_from_string (text); +#endif + + return (result ? savestring (result) : (char *)NULL); +} + +/* Initialize the tilde expander. In Bash, we handle `~-' and `~+', as + well as handling special tilde prefixes; `:~" and `=~' are indications + that we should do tilde expansion. */ +void +tilde_initialize () +{ + static int times_called = 0; + + /* Tell the tilde expander that we want a crack first. */ + tilde_expansion_preexpansion_hook = bash_special_tilde_expansions; + + /* Tell the tilde expander about special strings which start a tilde + expansion, and the special strings that end one. Only do this once. + tilde_initialize () is called from within bashline_reinitialize (). */ + if (times_called++ == 0) + { + bash_tilde_prefixes = strvec_create (3); + bash_tilde_prefixes[0] = "=~"; + bash_tilde_prefixes[1] = ":~"; + bash_tilde_prefixes[2] = (char *)NULL; + + bash_tilde_prefixes2 = strvec_create (2); + bash_tilde_prefixes2[0] = ":~"; + bash_tilde_prefixes2[1] = (char *)NULL; + + tilde_additional_prefixes = bash_tilde_prefixes; + + bash_tilde_suffixes = strvec_create (3); + bash_tilde_suffixes[0] = ":"; + bash_tilde_suffixes[1] = "=~"; /* XXX - ?? */ + bash_tilde_suffixes[2] = (char *)NULL; + + tilde_additional_suffixes = bash_tilde_suffixes; + + bash_tilde_suffixes2 = strvec_create (2); + bash_tilde_suffixes2[0] = ":"; + bash_tilde_suffixes2[1] = (char *)NULL; + } +} + +/* POSIX.2, 3.6.1: A tilde-prefix consists of an unquoted tilde character + at the beginning of the word, followed by all of the characters preceding + the first unquoted slash in the word, or all the characters in the word + if there is no slash...If none of the characters in the tilde-prefix are + quoted, the characters in the tilde-prefix following the tilde shell be + treated as a possible login name. */ + +#define TILDE_END(c) ((c) == '\0' || (c) == '/' || (c) == ':') + +static int +unquoted_tilde_word (s) + const char *s; +{ + const char *r; + + for (r = s; TILDE_END(*r) == 0; r++) + { + switch (*r) + { + case '\\': + case '\'': + case '"': + return 0; + } + } + return 1; +} + +/* Find the end of the tilde-prefix starting at S, and return the tilde + prefix in newly-allocated memory. Return the length of the string in + *LENP. FLAGS tells whether or not we're in an assignment context -- + if so, `:' delimits the end of the tilde prefix as well. */ +char * +bash_tilde_find_word (s, flags, lenp) + const char *s; + int flags, *lenp; +{ + const char *r; + char *ret; + int l; + + for (r = s; *r && *r != '/'; r++) + { + /* Short-circuit immediately if we see a quote character. Even though + POSIX says that `the first unquoted slash' (or `:') terminates the + tilde-prefix, in practice, any quoted portion of the tilde prefix + will cause it to not be expanded. */ + if (*r == '\\' || *r == '\'' || *r == '"') + { + ret = savestring (s); + if (lenp) + *lenp = 0; + return ret; + } + else if (flags && *r == ':') + break; + } + l = r - s; + ret = xmalloc (l + 1); + strncpy (ret, s, l); + ret[l] = '\0'; + if (lenp) + *lenp = l; + return ret; +} + +/* Tilde-expand S by running it through the tilde expansion library. + ASSIGN_P is 1 if this is a variable assignment, so the alternate + tilde prefixes should be enabled (`=~' and `:~', see above). If + ASSIGN_P is 2, we are expanding the rhs of an assignment statement, + so `=~' is not valid. */ +char * +bash_tilde_expand (s, assign_p) + const char *s; + int assign_p; +{ + int r; + char *ret; + + tilde_additional_prefixes = assign_p == 0 ? (char **)0 + : (assign_p == 2 ? bash_tilde_prefixes2 : bash_tilde_prefixes); + if (assign_p == 2) + tilde_additional_suffixes = bash_tilde_suffixes2; + + r = (*s == '~') ? unquoted_tilde_word (s) : 1; + ret = r ? tilde_expand (s) : savestring (s); + + QUIT; + + return (ret); +} + +/* **************************************************************** */ +/* */ +/* Functions to manipulate and search the group list */ +/* */ +/* **************************************************************** */ + +static int ngroups, maxgroups; + +/* The set of groups that this user is a member of. */ +static GETGROUPS_T *group_array = (GETGROUPS_T *)NULL; + +#if !defined (NOGROUP) +# define NOGROUP (gid_t) -1 +#endif + +static void +initialize_group_array () +{ + register int i; + + if (maxgroups == 0) + maxgroups = getmaxgroups (); + + ngroups = 0; + group_array = (GETGROUPS_T *)xrealloc (group_array, maxgroups * sizeof (GETGROUPS_T)); + +#if defined (HAVE_GETGROUPS) + ngroups = getgroups (maxgroups, group_array); +#endif + + /* If getgroups returns nothing, or the OS does not support getgroups(), + make sure the groups array includes at least the current gid. */ + if (ngroups == 0) + { + group_array[0] = current_user.gid; + ngroups = 1; + } + + /* If the primary group is not in the groups array, add it as group_array[0] + and shuffle everything else up 1, if there's room. */ + for (i = 0; i < ngroups; i++) + if (current_user.gid == (gid_t)group_array[i]) + break; + if (i == ngroups && ngroups < maxgroups) + { + for (i = ngroups; i > 0; i--) + group_array[i] = group_array[i - 1]; + group_array[0] = current_user.gid; + ngroups++; + } + + /* If the primary group is not group_array[0], swap group_array[0] and + whatever the current group is. The vast majority of systems should + not need this; a notable exception is Linux. */ + if (group_array[0] != current_user.gid) + { + for (i = 0; i < ngroups; i++) + if (group_array[i] == current_user.gid) + break; + if (i < ngroups) + { + group_array[i] = group_array[0]; + group_array[0] = current_user.gid; + } + } +} + +/* Return non-zero if GID is one that we have in our groups list. */ +int +#if defined (__STDC__) || defined ( _MINIX) +group_member (gid_t gid) +#else +group_member (gid) + gid_t gid; +#endif /* !__STDC__ && !_MINIX */ +{ +#if defined (HAVE_GETGROUPS) + register int i; +#endif + + /* Short-circuit if possible, maybe saving a call to getgroups(). */ + if (gid == current_user.gid || gid == current_user.egid) + return (1); + +#if defined (HAVE_GETGROUPS) + if (ngroups == 0) + initialize_group_array (); + + /* In case of error, the user loses. */ + if (ngroups <= 0) + return (0); + + /* Search through the list looking for GID. */ + for (i = 0; i < ngroups; i++) + if (gid == (gid_t)group_array[i]) + return (1); +#endif + + return (0); +} + +char ** +get_group_list (ngp) + int *ngp; +{ + static char **group_vector = (char **)NULL; + register int i; + + if (group_vector) + { + if (ngp) + *ngp = ngroups; + return group_vector; + } + + if (ngroups == 0) + initialize_group_array (); + + if (ngroups <= 0) + { + if (ngp) + *ngp = 0; + return (char **)NULL; + } + + group_vector = strvec_create (ngroups); + for (i = 0; i < ngroups; i++) + group_vector[i] = itos (group_array[i]); + + if (ngp) + *ngp = ngroups; + return group_vector; +} + +int * +get_group_array (ngp) + int *ngp; +{ + int i; + static int *group_iarray = (int *)NULL; + + if (group_iarray) + { + if (ngp) + *ngp = ngroups; + return (group_iarray); + } + + if (ngroups == 0) + initialize_group_array (); + + if (ngroups <= 0) + { + if (ngp) + *ngp = 0; + return (int *)NULL; + } + + group_iarray = (int *)xmalloc (ngroups * sizeof (int)); + for (i = 0; i < ngroups; i++) + group_iarray[i] = (int)group_array[i]; + + if (ngp) + *ngp = ngroups; + return group_iarray; +} + +/* **************************************************************** */ +/* */ +/* Miscellaneous functions */ +/* */ +/* **************************************************************** */ + +/* Return a value for PATH that is guaranteed to find all of the standard + utilities. This uses Posix.2 configuration variables, if present. It + uses a value defined in config.h as a last resort. */ +char * +conf_standard_path () +{ +#if defined (_CS_PATH) && defined (HAVE_CONFSTR) + char *p; + size_t len; + + len = (size_t)confstr (_CS_PATH, (char *)NULL, (size_t)0); + if (len > 0) + { + p = (char *)xmalloc (len + 2); + *p = '\0'; + confstr (_CS_PATH, p, len); + return (p); + } + else + return (savestring (STANDARD_UTILS_PATH)); +#else /* !_CS_PATH || !HAVE_CONFSTR */ +# if defined (CS_PATH) + return (savestring (CS_PATH)); +# else + return (savestring (STANDARD_UTILS_PATH)); +# endif /* !CS_PATH */ +#endif /* !_CS_PATH || !HAVE_CONFSTR */ +} + +int +default_columns () +{ + char *v; + int c; + + c = -1; + v = get_string_value ("COLUMNS"); + if (v && *v) + { + c = atoi (v); + if (c > 0) + return c; + } + + if (check_window_size) + get_new_window_size (0, (int *)0, &c); + + return (c > 0 ? c : 80); +} + + |