coreutils/lib/savedir.c
Jim Meyering 2c63fed0e8 (savedir): Remove size parameter, as POSIX says that
a directory's st_size can have an arbitrary value, so the old
usage could waste an arbitrary amount of memory.  All uses
changed.
2001-08-31 09:09:53 +00:00

130 lines
3.0 KiB
C

/* savedir.c -- save the list of files in a directory in a string
Copyright 1990, 1997, 1998, 1999, 2000, 2001 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 02111-1307, USA. */
/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#include <errno.h>
#ifndef errno
extern int errno;
#endif
#if HAVE_DIRENT_H
# include <dirent.h>
#else
# define dirent direct
# if HAVE_SYS_NDIR_H
# include <sys/ndir.h>
# endif
# if HAVE_SYS_DIR_H
# include <sys/dir.h>
# endif
# if HAVE_NDIR_H
# include <ndir.h>
# endif
#endif
#ifdef CLOSEDIR_VOID
/* Fake a return value. */
# define CLOSEDIR(d) (closedir (d), 0)
#else
# define CLOSEDIR(d) closedir (d)
#endif
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <string.h>
#endif
#ifndef NULL
# define NULL 0
#endif
#include "savedir.h"
#include "xalloc.h"
/* Return a freshly allocated string containing the filenames
in directory DIR, separated by '\0' characters;
the end is marked by two '\0' characters in a row.
Return NULL (setting errno) if DIR cannot be opened, read, or closed. */
#ifndef NAME_SIZE_DEFAULT
# define NAME_SIZE_DEFAULT 512
#endif
char *
savedir (const char *dir)
{
DIR *dirp;
struct dirent *dp;
char *name_space;
size_t allocated = NAME_SIZE_DEFAULT;
size_t used = 0;
int save_errno;
dirp = opendir (dir);
if (dirp == NULL)
return NULL;
name_space = xmalloc (allocated);
errno = 0;
while ((dp = readdir (dirp)) != NULL)
{
/* Skip "", ".", and "..". "" is returned by at least one buggy
implementation: Solaris 2.4 readdir on NFS filesystems. */
char const *entry = dp->d_name;
if (entry[entry[0] != '.' ? 0 : entry[1] != '.' ? 1 : 2] != '\0')
{
size_t entry_size = strlen (entry) + 1;
if (used + entry_size < used)
xalloc_die ();
if (allocated <= used + entry_size)
{
do
{
if (2 * allocated < allocated)
xalloc_die ();
allocated *= 2;
}
while (allocated <= used + entry_size);
name_space = xrealloc (name_space, allocated);
}
memcpy (name_space + used, entry, entry_size);
used += entry_size;
}
}
name_space[used] = '\0';
save_errno = errno;
if (CLOSEDIR (dirp) != 0)
save_errno = errno;
if (save_errno != 0)
{
free (name_space);
errno = save_errno;
return NULL;
}
return name_space;
}