support.c

   1 /*
   2
   3     Ann Hell Ex Machina - Music Software
   4     Copyright (C) 2003/2005 Angel Ortega <angel@triptico.com>
   5
   6     support.c - Miscellaneous support functions
   7
   8     This program is free software; you can redistribute it and/or
   9     modify it under the terms of the GNU General Public License
  10     as published by the Free Software Foundation; either version 2
  11     of the License, or (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21
  22     http://www.triptico.com
  23
  24 */
  25
  26 #include "config.h"
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31
  32 #include "annhell.h"
  33
  34 /*******************
  35         Data
  36 ********************/
  37
  38 static char ** library_path = NULL;
  39 static int n_library_paths = 0;
  40
  41 static char located_file[2048];
  42
  43 /* global debugging flag */
  44 int debug = 0;
  45
  46 /* global tracing flag */
  47 int trace = 0;
  48
  49 /* show progress flag */
  50 int show_progress = 0;
  51
  52 /*******************
  53         Code
  54 ********************/
  55
  56 /**
  57  * add_to_library_path - Adds a directory path to the search path
  58  * @path: the directory path
  59  * @strip: flag to strip the upper level
  60  *
  61  * Adds @path to the list of searchable paths for path_fopen(),
  62  * optionally stripping the upper level if @strip is set.
  63  * The last part of the path is stripped before being stored,
  64  * and duplication is avoided.
  65  */
  66 void add_to_library_path(char * path, int strip)
  67 {
  68         int n;
  69         char * ptr;
  70
  71         /* if path starts with ~, pre-prend $HOME */
  72         if(*path == '~')
  73         {
  74                 char * new;
  75                 char * home;
  76
  77                 if((home = getenv("HOME")) == NULL)
  78                         return;
  79
  80                 if((new = malloc(strlen(home) + strlen(path) + 2)) == NULL)
  81                         return;
  82
  83                 strcpy(new, home);
  84                 strcat(new, "/");
  85                 strcat(new, path + 1);
  86
  87                 path = new;
  88         }
  89         else
  90         {
  91                 /* just duplicate */
  92                 path = strdup(path);
  93         }
  94
  95         /* if no directory path remains, abort */
  96         if((ptr = strrchr(path, '/')) == NULL)
  97         {
  98                 free(path);
  99                 return;
 100         }
 101
 102         /* strip the filename part */
 103         if(strip) *ptr = '\0';
 104
 105         /* now try to find if that path is already stored */
 106         for(n = 0;n < n_library_paths;n++)
 107         {
 108                 if(strcmp(path, library_path[n]) == 0)
 109                 {
 110                         /* found; free and return */
 111                         free(path);
 112                         return;
 113                 }
 114         }
 115
 116         /* add room for the new path */
 117         n_library_paths++;
 118         library_path = (char **)realloc(library_path,
 119                 n_library_paths * sizeof(char *));
 120
 121         /* store */
 122         library_path[n_library_paths - 1] = path;
 123 }
 124
 125
 126 /**
 127  * path_fopen - Opens a file, optionally searching in a path list
 128  * @filename: the file name
 129  * @mode: the file mode
 130  *
 131  * Opens a file. If the file is found as is, it's opened;
 132  * otherwise, the full list of directory paths maintained by
 133  * add_to_library_path() is searched until it's found or the
 134  * end of the list is reached. Whenever a file
 135  * is successfully opened, its path is also stored.
 136  */
 137 FILE * path_fopen(char * filename, char * mode)
 138 {
 139         int n;
 140         FILE * f = NULL;
 141
 142         /* try first here */
 143         if((f = fopen(filename, mode)) != NULL)
 144         {
 145                 strncpy(located_file, filename, sizeof(located_file));
 146                 located_file[sizeof(located_file) - 1] = '\0';
 147
 148                 add_to_library_path(filename, 1);
 149                 return(f);
 150         }
 151
 152         /* couldn't open; try concatenating all stored paths */
 153         for(n = n_library_paths - 1;n >= 0;n--)
 154         {
 155                 snprintf(located_file, sizeof(located_file), "%s/%s",
 156                         library_path[n], filename);
 157                 located_file[sizeof(located_file) - 1] = '\0';
 158
 159                 if((f = fopen(located_file, mode)) != NULL)
 160                 {
 161                         add_to_library_path(located_file, 1);
 162                         break;
 163                 }
 164         }
 165
 166         return(f);
 167 }
 168
 169
 170 /**
 171  * locate_file - Locates a file inside the path
 172  * @filename: the file to be located
 173  *
 174  * Locates a file inside the library path maintained by path_fopen()
 175  * and add_library_path(). If the file is found, a pointer to a static
 176  * buffer containing the real path of the file is returned, or
 177  * NULL otherwise.
 178  */
 179 char * locate_file(char * filename)
 180 {
 181         FILE * f;
 182
 183         if((f = path_fopen(filename, "r")) == NULL)
 184                 return(NULL);
 185
 186         fclose(f);
 187         return(located_file);
 188 }