src/text/filesystem.c

   1 /*****************************************************************************
   2  * filesystem.c: Common file system helpers
   3  *****************************************************************************
   4  * Copyright (C) 2005-2006 VLC authors and VideoLAN
   5  * Copyright © 2005-2008 Rémi Denis-Courmont
   6  *
   7  * Authors: Rémi Denis-Courmont <rem # videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_fs.h>
  33
  34 #include <assert.h>
  35
  36 #include <stdio.h>
  37 #include <errno.h>
  38 #include <sys/types.h>
  39 #include <fcntl.h>
  40 #include <unistd.h>
  41
  42 /**
  43  * Opens a FILE pointer.
  44  * @param filename file path, using UTF-8 encoding
  45  * @param mode fopen file open mode
  46  * @return NULL on error, an open FILE pointer on success.
  47  */
  48 FILE *vlc_fopen (const char *filename, const char *mode)
  49 {
  50     int rwflags = 0, oflags = 0;
  51
  52     for (const char *ptr = mode; *ptr; ptr++)
  53     {
  54         switch (*ptr)
  55         {
  56             case 'r':
  57                 rwflags = O_RDONLY;
  58                 break;
  59
  60             case 'a':
  61                 rwflags = O_WRONLY;
  62                 oflags |= O_CREAT | O_APPEND;
  63                 break;
  64
  65             case 'w':
  66                 rwflags = O_WRONLY;
  67                 oflags |= O_CREAT | O_TRUNC;
  68                 break;
  69
  70             case 'x':
  71                 oflags |= O_EXCL;
  72                 break;
  73
  74             case '+':
  75                 rwflags = O_RDWR;
  76                 break;
  77
  78 #ifdef O_BINARY
  79             case 'b':
  80                 oflags = (oflags & ~O_TEXT) | O_BINARY;
  81                 break;
  82
  83             case 't':
  84                 oflags = (oflags & ~O_BINARY) | O_TEXT;
  85                 break;
  86 #endif
  87         }
  88     }
  89
  90     int fd = vlc_open (filename, rwflags | oflags, 0666);
  91     if (fd == -1)
  92         return NULL;
  93
  94     FILE *stream = fdopen (fd, mode);
  95     if (stream == NULL)
  96         vlc_close (fd);
  97
  98     return stream;
  99 }
 100
 101
 102 static int dummy_select( const char *str )
 103 {
 104     (void)str;
 105     return 1;
 106 }
 107
 108 /**
 109  * Does the same as vlc_scandir(), but takes an open directory pointer
 110  * instead of a directory path.
 111  */
 112 int vlc_loaddir( DIR *dir, char ***namelist,
 113                   int (*select)( const char * ),
 114                   int (*compar)( const char **, const char ** ) )
 115 {
 116     assert (dir);
 117
 118     if (select == NULL)
 119         select = dummy_select;
 120
 121     char **tab = NULL;
 122     unsigned num = 0;
 123
 124     rewinddir (dir);
 125
 126     for (unsigned size = 0;;)
 127     {
 128         errno = 0;
 129         const char *entry = vlc_readdir (dir);
 130         if (entry == NULL)
 131         {
 132             if (errno)
 133                 goto error;
 134             break;
 135         }
 136
 137         if (!select (entry))
 138             continue;
 139
 140         if (num >= size)
 141         {
 142             size = size ? (2 * size) : 16;
 143             char **newtab = realloc (tab, sizeof (*tab) * (size));
 144
 145             if (unlikely(newtab == NULL))
 146                 goto error;
 147             tab = newtab;
 148         }
 149
 150         tab[num] = strdup(entry);
 151         if (likely(tab[num] != NULL))
 152             num++;
 153     }
 154
 155     if (compar != NULL && num > 0)
 156         qsort (tab, num, sizeof (*tab),
 157                (int (*)( const void *, const void *))compar);
 158     *namelist = tab;
 159     return num;
 160
 161 error:
 162     for (unsigned i = 0; i < num; i++)
 163         free (tab[i]);
 164     free (tab);
 165     return -1;
 166 }
 167
 168 /**
 169  * Selects file entries from a directory, as GNU C scandir().
 170  *
 171  * @param dirname UTF-8 diretory path
 172  * @param pointer [OUT] pointer set, on successful completion, to the address
 173  * of a table of UTF-8 filenames. All filenames must be freed with free().
 174  * The table itself must be freed with free() as well.
 175  *
 176  * @return How many file names were selected (possibly 0),
 177  * or -1 in case of error.
 178  */
 179 int vlc_scandir( const char *dirname, char ***namelist,
 180                   int (*select)( const char * ),
 181                   int (*compar)( const char **, const char ** ) )
 182 {
 183     DIR *dir = vlc_opendir (dirname);
 184     int val = -1;
 185
 186     if (dir != NULL)
 187     {
 188         val = vlc_loaddir (dir, namelist, select, compar);
 189         closedir (dir);
 190     }
 191     return val;
 192 }
 193
 194 #if defined (_WIN32) || defined (__OS2__)
 195 # include <vlc_rand.h>
 196
 197 int vlc_mkstemp( char *template )
 198 {
 199     static const char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 200     static const int i_digits = sizeof(digits)/sizeof(*digits) - 1;
 201
 202     /* */
 203     assert( template );
 204
 205     /* Check template validity */
 206     const size_t i_length = strlen( template );
 207     char *psz_rand = &template[i_length-6];
 208
 209     if( i_length < 6 || strcmp( psz_rand, "XXXXXX" ) )
 210     {
 211         errno = EINVAL;
 212         return -1;
 213     }
 214
 215     /* */
 216     for( int i = 0; i < 256; i++ )
 217     {
 218         /* Create a pseudo random file name */
 219         uint8_t pi_rand[6];
 220
 221         vlc_rand_bytes( pi_rand, sizeof(pi_rand) );
 222         for( int j = 0; j < 6; j++ )
 223             psz_rand[j] = digits[pi_rand[j] % i_digits];
 224
 225         /* */
 226         int fd = vlc_open( template, O_CREAT | O_EXCL | O_RDWR, 0600 );
 227         if( fd >= 0 )
 228             return fd;
 229         if( errno != EEXIST )
 230             return -1;
 231     }
 232
 233     errno = EEXIST;
 234     return -1;
 235 }
 236 #endif