glob.c

UNIX下SH的实现源码

/* File-name wildcard pattern matching for GNU.
   Copyright (C) 1985, 1988, 1989 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 2, 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, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA.  */

/* To whomever it may concern: I have never seen the code which most
   Unix programs use to perform this function.  I wrote this from scratch
   based on specifications for the pattern matching.  --RMS.  */

#include <config.h>

#if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
  #pragma alloca
#endif /* _AIX && RISC6000 && !__GNUC__ */

#if defined (SHELL)
#  include "bashtypes.h"
#else
#  include <sys/types.h>
#endif

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#if defined (SHELL)
#  include "bashansi.h"
#else
#  if defined (HAVE_STDLIB_H)
#    include <stdlib.h>
#  endif
#  if defined (HAVE_STRING_H)
#    include <string.h>
#  else /* !HAVE_STRING_H */
#    include <strings.h>
#  endif /* !HAVE_STRING_H */
#endif

#if defined (HAVE_DIRENT_H)
#  include <dirent.h>
#  define D_NAMLEN(d) strlen ((d)->d_name)
#else /* !HAVE_DIRENT_H */
#  define D_NAMLEN(d) ((d)->d_namlen)
#  if defined (HAVE_SYS_NDIR_H)
#    include <sys/ndir.h>
#  endif
#  if defined (HAVE_SYS_DIR_H)
#    include <sys/dir.h>
#  endif /* HAVE_SYS_DIR_H */
#  if defined (HAVE_NDIR_H)
#    include <ndir.h>
#  endif
#  if !defined (dirent)
#    define dirent direct
#  endif
#endif /* !HAVE_DIRENT_H */

#if defined (_POSIX_SOURCE) || !defined (STRUCT_DIRENT_HAS_D_INO)
/* Posix does not require that the d_ino field be present, and some
   systems do not provide it. */
#  define REAL_DIR_ENTRY(dp) 1
#else
#  define REAL_DIR_ENTRY(dp) (dp->d_ino != 0)
#endif /* _POSIX_SOURCE */

#if !defined (HAVE_BCOPY) && !defined (bcopy)
#  define bcopy(s, d, n) ((void) memcpy ((d), (s), (n)))
#endif /* !HAVE_BCOPY && !bcopy */

#if defined (SHELL)
#  include "posixstat.h"
#else /* !SHELL */
#  include <sys/stat.h>
#endif /* !SHELL */

#include "filecntl.h"
#if !defined (F_OK)
#  define F_OK 0
#endif

#if defined (SHELL)
#  include "memalloc.h"
#endif

#include "fnmatch.h"

#if !defined (HAVE_STDLIB_H) && !defined (SHELL)
extern char *malloc (), *realloc ();
extern void free ();
#endif /* !HAVE_STDLIB_H */

#if !defined (NULL)
#  if defined (__STDC__)
#    define NULL ((void *) 0)
#  else
#    define NULL 0x0
#  endif /* __STDC__ */
#endif /* !NULL */

#if defined (SHELL)
extern void throw_to_top_level ();
extern int test_eaccess ();

extern int interrupt_state;
extern int extended_glob;
#endif /* SHELL */

#if defined (__MSDOS__)
#include "dosutil.h"
#endif

/* Global variable which controls whether or not * matches .*.
   Non-zero means don't match .*.  */
int noglob_dot_filenames = 1;

/* Global variable which controls whether or not filename globbing
   is done without regard to case. */
int glob_ignore_case = 0;

/* Global variable to return to signify an error in globbing. */
char *glob_error_return;

/* Return nonzero if PATTERN has any special globbing chars in it.  */
int
glob_pattern_p (pattern)
     char *pattern;
{
  register char *p;
  register char c;
  int bopen;

  p = pattern;
  bopen = 0;

  while ((c = *p++) != '\0')
    switch (c)
      {
      case '?':
      case '*':
	return (1);

      case '[':		/* Only accept an open brace if there is a close */
	bopen++;	/* brace to match it.  Bracket expressions must be */
	continue;	/* complete, according to Posix.2 */
      case ']':
	if (bopen)
	  return (1);
	continue;      

      case '+':		/* extended matching operators */
      case '@':
      case '!':
	if (*p == '(')	/*) */
	  return (1);
	continue;

      case '\\':
	if (*p++ == '\0')
	  return (0);
      }

  return (0);
}

/* Remove backslashes quoting characters in PATHNAME by modifying PATHNAME. */
static void
dequote_pathname (pathname)
     char *pathname;
{
  register int i, j;

  for (i = j = 0; pathname && pathname[i]; )
    {
      if (pathname[i] == '\\')
	i++;

      pathname[j++] = pathname[i++];

      if (!pathname[i - 1])
	break;
    }
  pathname[j] = '\0';
}



/* Test whether NAME exists. */

#if defined (HAVE_LSTAT)
#  define GLOB_TESTNAME(name)  (lstat (name, &finfo))
#else /* !HAVE_LSTAT */
#  if defined (SHELL) && !defined (AFS)
#    define GLOB_TESTNAME(name)  (test_eaccess (nextname, F_OK))
#  else /* !SHELL || AFS */
#    define GLOB_TESTNAME(name)  (access (nextname, F_OK))
#  endif /* !SHELL || AFS */
#endif /* !HAVE_LSTAT */

/* Return 0 if DIR is a directory, -1 otherwise. */
static int
glob_testdir (dir)
     char *dir;
{
  struct stat finfo;

  if (stat (dir, &finfo) < 0)
    return (-1);

  if (S_ISDIR (finfo.st_mode) == 0)
    return (-1);

  return (0);
}

/* Return a vector of names of files in directory DIR
   whose names match glob pattern PAT.
   The names are not in any particular order.
   Wildcards at the beginning of PAT do not match an initial period.

   The vector is terminated by an element that is a null pointer.

   To free the space allocated, first free the vector's elements,
   then free the vector.

   Return 0 if cannot get enough memory to hold the pointer
   and the names.

   Return -1 if cannot access directory DIR.
   Look in errno for more information.  */

char **
glob_vector (pat, dir)
     char *pat;
     char *dir;
{
  struct globval
    {
      struct globval *next;
      char *name;
    };

#if defined (__MSDOS__)
  char *fixp;
  int use_lfn = (pathconf (NULL, _PC_NAME_MAX) > 12);
#endif
  DIR *d;
  register struct dirent *dp;
  struct globval *lastlink;
  register struct globval *nextlink;
  register char *nextname, *npat;
  unsigned int count;
  int lose, skip;
  register char **name_vector;
  register unsigned int i;
  int flags;		/* Flags passed to fnmatch (). */

  lastlink = 0;
  count = lose = skip = 0;

  /* If PAT is empty, skip the loop, but return one (empty) filename. */
  if (pat == 0 || *pat == '\0')
    {
      if (glob_testdir (dir) < 0)
	return ((char **) &glob_error_return);

      nextlink = (struct globval *)alloca (sizeof (struct globval));
      nextlink->next = (struct globval *)0;
      nextname = (char *) malloc (1);
      if (nextname == 0)
	lose = 1;
      else
	{
	  lastlink = nextlink;
	  nextlink->name = nextname;
	  nextname[0] = '\0';
	  count = 1;
	}

      skip = 1;
    }

  /* If the filename pattern (PAT) does not contain any globbing characters,
     we can dispense with reading the directory, and just see if there is
     a filename `DIR/PAT'.  If there is, and we can access it, just make the
     vector to return and bail immediately. */
  if (skip == 0 && glob_pattern_p (pat) == 0)
    {
      int dirlen;
      struct stat finfo;

      if (glob_testdir (dir) < 0)
	return ((char **) &glob_error_return);

      dirlen = strlen (dir);
      nextname = (char *)malloc (dirlen + strlen (pat) + 2);
      npat = (char *)malloc (strlen (pat) + 1);
      if (nextname == 0 || npat == 0)
	lose = 1;
      else
	{
	  strcpy (npat, pat);
	  dequote_pathname (npat);

	  strcpy (nextname, dir);
	  nextname[dirlen++] = '/';
	  strcpy (nextname + dirlen, npat);

	  if (GLOB_TESTNAME (nextname) >= 0)
	    {
	      free (nextname);
	      nextlink = (struct globval *)alloca (sizeof (struct globval));
	      nextlink->next = (struct globval *)0;
	      lastlink = nextlink;
	      nextlink->name = npat;
	      count = 1;
	    }
	  else
	    {
	      free (nextname);
	      free (npat);
	    }
	}

      skip = 1;
    }

  if (skip == 0)
    {
      /* Open the directory, punting immediately if we cannot.  If opendir
	 is not robust (i.e., it opens non-directories successfully), test
	 that DIR is a directory and punt if it's not. */
#if defined (OPENDIR_NOT_ROBUST)
      if (glob_testdir (dir) < 0)
	return ((char **) &glob_error_return);
#endif

      d = opendir (dir);
      if (d == NULL)
	return ((char **) &glob_error_return);

      /* Compute the flags that will be passed to fnmatch().  We don't
         need to do this every time through the loop. */
      flags = (noglob_dot_filenames ? FNM_PERIOD : 0) | FNM_PATHNAME;

#ifdef FNM_CASEFOLD
#if defined (__DJGPP__)
      /* DJGPP's globbing does not ignore case
         when in an LFN environment and either FNCASE=Y
         or an uppercase letter is in the pattern. */

      glob_ignore_case = !(use_lfn && (_preserve_fncase() != 0));
      if (glob_ignore_case && use_lfn)
        {
          char *cur_pat = pat;
          char ch;
          while ((ch = *cur_pat++))
            {
              if ((ch >= 'A') && (ch <= 'Z'))
                {
                  glob_ignore_case = 0;
                  break;
                }
            }
        }
#endif
      if (glob_ignore_case)
	flags |= FNM_CASEFOLD;
#endif