1/* savedir.c -- save the list of files in a directory in a string 2 3 Copyright (C) 1990, 1997-2001, 2003-2006, 2009-2010 Free Software 4 Foundation, Inc. 5 6 This program is free software: you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 18 19/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */ 20 21#include <config.h> 22 23#include "savedir.h" 24 25#include <sys/types.h> 26 27#include <errno.h> 28 29#include "dirent--.h" 30#ifndef _D_EXACT_NAMLEN 31# define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name) 32#endif 33 34#include <stddef.h> 35#include <stdlib.h> 36#include <string.h> 37 38#include "xalloc.h" 39 40#ifndef NAME_SIZE_DEFAULT 41# define NAME_SIZE_DEFAULT 512 42#endif 43 44/* Return a freshly allocated string containing the file names 45 in directory DIRP, separated by '\0' characters; 46 the end is marked by two '\0' characters in a row. 47 Return NULL (setting errno) if DIRP cannot be read or closed. 48 If DIRP is NULL, return NULL without affecting errno. */ 49 50static char * 51savedirstream (DIR *dirp) 52{ 53 char *name_space; 54 size_t allocated = NAME_SIZE_DEFAULT; 55 size_t used = 0; 56 int save_errno; 57 58 if (dirp == NULL) 59 return NULL; 60 61 name_space = xmalloc (allocated); 62 63 for (;;) 64 { 65 struct dirent const *dp; 66 char const *entry; 67 68 errno = 0; 69 dp = readdir (dirp); 70 if (! dp) 71 break; 72 73 /* Skip "", ".", and "..". "" is returned by at least one buggy 74 implementation: Solaris 2.4 readdir on NFS file systems. */ 75 entry = dp->d_name; 76 if (entry[entry[0] != '.' ? 0 : entry[1] != '.' ? 1 : 2] != '\0') 77 { 78 size_t entry_size = _D_EXACT_NAMLEN (dp) + 1; 79 if (used + entry_size < used) 80 xalloc_die (); 81 if (allocated <= used + entry_size) 82 { 83 do 84 { 85 if (2 * allocated < allocated) 86 xalloc_die (); 87 allocated *= 2; 88 } 89 while (allocated <= used + entry_size); 90 91 name_space = xrealloc (name_space, allocated); 92 } 93 memcpy (name_space + used, entry, entry_size); 94 used += entry_size; 95 } 96 } 97 name_space[used] = '\0'; 98 save_errno = errno; 99 if (closedir (dirp) != 0) 100 save_errno = errno; 101 if (save_errno != 0) 102 { 103 free (name_space); 104 errno = save_errno; 105 return NULL; 106 } 107 return name_space; 108} 109 110/* Return a freshly allocated string containing the file names 111 in directory DIR, separated by '\0' characters; 112 the end is marked by two '\0' characters in a row. 113 Return NULL (setting errno) if DIR cannot be opened, read, or closed. */ 114 115char * 116savedir (char const *dir) 117{ 118 return savedirstream (opendir (dir)); 119} 120 121/* Return a freshly allocated string containing the file names 122 in directory FD, separated by '\0' characters; 123 the end is marked by two '\0' characters in a row. 124 Return NULL (setting errno) if FD cannot be read or closed. */ 125 126char * 127fdsavedir (int fd) 128{ 129 return savedirstream (fdopendir (fd)); 130} 131