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 /*******************
  42         Code
  43 ********************/
  44
  45 /**
  46  * add_to_library_path - Adds a directory path to the search path
  47  * @path: the directory path
  48  *
  49  * Adds @path to the list of searchable paths for path_fopen().
  50  * The last part of the path is stripped before being stored,
  51  * and duplication is avoided.
  52  */
  53 void add_to_library_path(char * path)
  54 {
  55         int n;
  56         char * ptr;
  57
  58         /* duplicate */
  59         path=strdup(path);
  60
  61         /* if no directory path remains, abort */
  62         if((ptr=strrchr(path, '/')) == NULL)
  63         {
  64                 free(path);
  65                 return;
  66         }
  67
  68         /* strip the filename part */
  69         *ptr='\0';
  70
  71         /* now try to find if that path is already stored */
  72         for(n=0;n < n_library_paths;n++)
  73         {
  74                 if(strcmp(path, library_path[n]) == 0)
  75                 {
  76                         /* found; free and return */
  77                         free(path);
  78                         return;
  79                 }
  80         }
  81
  82         /* add room for the new path */
  83         n_library_paths++;
  84         library_path=(char **)realloc(library_path,
  85                 n_library_paths * sizeof(char *));
  86
  87         /* store */
  88         library_path[n_library_paths - 1]=path;
  89 }
  90
  91
  92 /**
  93  * path_fopen - Opens a file, optionally searching in a path list
  94  * @filename: the file name
  95  * @mode: the file mode
  96  *
  97  * Opens a file. If the file is found as is, it's opened;
  98  * otherwise, the full list of directory paths maintained by
  99  * add_to_library_path() is searched until it's found or the
 100  * end of the list is reached. Whenever a file
 101  * is successfully opened, its path is also stored.
 102  */
 103 FILE * path_fopen(char * filename, char * mode)
 104 {
 105         int n;
 106         FILE * f=NULL;
 107
 108         /* try first here */
 109         if((f=fopen(filename, mode)) != NULL)
 110         {
 111                 add_to_library_path(filename);
 112                 return(f);
 113         }
 114
 115         /* couldn't open; try concatenating all stored paths */
 116         for(n=n_library_paths - 1;n >= 0;n--)
 117         {
 118                 char tmp[4096];
 119
 120                 snprintf(tmp, sizeof(tmp) - 1, "%s/%s",
 121                         library_path[n], filename);
 122                 tmp[sizeof(tmp) - 1]='\0';
 123
 124                 if((f=fopen(tmp, mode)) != NULL)
 125                 {
 126                         add_to_library_path(tmp);
 127                         break;
 128                 }
 129         }
 130
 131         return(f);
 132 }
 133
 134