/* savedir.c -- save the list of files in a directory in a string Copyright (C) 1990, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */ #include <config.h> #include "savedir.h" #include <sys/types.h> #include <errno.h> #include <dirent.h> #ifndef _D_EXACT_NAMLEN # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name) #endif #include <stddef.h> #include <stdlib.h> #include <string.h> #include "openat.h" #include "xalloc.h" #ifndef NAME_SIZE_DEFAULT # define NAME_SIZE_DEFAULT 512 #endif /* The results of opendir() in this file are not used with dirfd and fchdir, therefore save some unnecessary work in fchdir.c. */ #undef opendir #undef closedir /* Return a freshly allocated string containing the file names in directory DIRP, separated by '\0' characters; the end is marked by two '\0' characters in a row. Return NULL (setting errno) if DIRP cannot be read or closed. If DIRP is NULL, return NULL without affecting errno. */ static char * savedirstream (DIR *dirp) { char *name_space; size_t allocated = NAME_SIZE_DEFAULT; size_t used = 0; int save_errno; if (dirp == NULL) return NULL; name_space = xmalloc (allocated); for (;;) { struct dirent const *dp; char const *entry; errno = 0; dp = readdir (dirp); if (! dp) break; /* Skip "", ".", and "..". "" is returned by at least one buggy implementation: Solaris 2.4 readdir on NFS file systems. */ entry = dp->d_name; if (entry[entry[0] != '.' ? 0 : entry[1] != '.' ? 1 : 2] != '\0') { size_t entry_size = _D_EXACT_NAMLEN (dp) + 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; } /* Return a freshly allocated string containing the file names 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. */ char * savedir (char const *dir) { return savedirstream (opendir (dir)); } /* Return a freshly allocated string containing the file names in directory FD, separated by '\0' characters; the end is marked by two '\0' characters in a row. Return NULL (setting errno) if FD cannot be read or closed. */ char * fdsavedir (int fd) { return savedirstream (fdopendir (fd)); }