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+/* general.c -- Stuff that is used by all files. */
+
+/* Copyright (C) 1987-2016 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 "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 __P((char *));
+static int unquoted_tilde_word __P((const char *));
+static void initialize_group_array __P((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
+
+ 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
+};
+
+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. */
+ if (on == 0)
+ {
+ 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;
+}
+
+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. Nor
+ does it consist of all digits. If CHECK_WORD is non-zero,
+ the word is checked to ensure that it consists of only letters,
+ digits, and underscores. */
+int
+check_identifier (word, check_word)
+ WORD_DESC *word;
+ int check_word;
+{
+ if ((word->flags & (W_HASDOLLAR|W_QUOTED)) || all_digits (word->word))
+ {
+ internal_error (_("`%s': not a valid identifier"), word->word);
+ return (0);
+ }
+ else if (check_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 don't want an array subscript before the `='. */
+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 ((legal_variable_starter (c) == 0) && ((flags&1) == 0 || c != '[')) /* ] */
+#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 __P((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 old_immed, old_term, r;
+ char *ret;
+
+#if 0
+ old_immed = interrupt_immediately;
+ old_term = terminate_immediately;
+ /* We want to be able to interrupt tilde expansion. Ordinarily, we can just
+ jump to top_level, but we don't want to run any trap commands in a signal
+ handler context. We might be able to get away with just checking for
+ things like SIGINT and SIGQUIT. */
+ if (any_signals_trapped () < 0)
+ interrupt_immediately = 1;
+ terminate_immediately = 1;
+#endif
+
+ 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);
+
+#if 0
+ interrupt_immediately = old_immed;
+ terminate_immediately = old_term;
+#endif
+
+ 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);
+}
+
+