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  * @strip: flag to strip the upper level
  49  *
  50  * Adds @path to the list of searchable paths for path_fopen(),
  51  * optionally stripping the upper level if @strip is set.
  52  * The last part of the path is stripped before being stored,
  53  * and duplication is avoided.
  54  */
  55 void add_to_library_path(char * path, int strip)
  56 {
  57         int n;
  58         char * ptr;
  59
  60         /* if path starts with ~, pre-prend $HOME */
  61         if(*path == '~')
  62         {
  63                 char * new;
  64                 char * home;
  65
  66                 if((home=getenv("HOME")) == NULL)
  67                         return;
  68
  69                 if((new=malloc(strlen(home) + strlen(path) + 2)) == NULL)
  70                         return;
  71
  72                 strcpy(new, home);
  73                 strcat(new, "/");
  74                 strcat(new, path + 1);
  75
  76                 path=new;
  77         }
  78         else
  79         {
  80                 /* just duplicate */
  81                 path=strdup(path);
  82         }
  83
  84         /* if no directory path remains, abort */
  85         if((ptr=strrchr(path, '/')) == NULL)
  86         {
  87                 free(path);
  88                 return;
  89         }
  90
  91         /* strip the filename part */
  92         if(strip) *ptr='\0';
  93
  94         /* now try to find if that path is already stored */
  95         for(n=0;n < n_library_paths;n++)
  96         {
  97                 if(strcmp(path, library_path[n]) == 0)
  98                 {
  99                         /* found; free and return */
 100                         free(path);
 101                         return;
 102                 }
 103         }
 104
 105         /* add room for the new path */
 106         n_library_paths++;
 107         library_path=(char **)realloc(library_path,
 108                 n_library_paths * sizeof(char *));
 109
 110         /* store */
 111         library_path[n_library_paths - 1]=path;
 112 }
 113
 114
 115 /**
 116  * path_fopen - Opens a file, optionally searching in a path list
 117  * @filename: the file name
 118  * @mode: the file mode
 119  *
 120  * Opens a file. If the file is found as is, it's opened;
 121  * otherwise, the full list of directory paths maintained by
 122  * add_to_library_path() is searched until it's found or the
 123  * end of the list is reached. Whenever a file
 124  * is successfully opened, its path is also stored.
 125  */
 126 FILE * path_fopen(char * filename, char * mode)
 127 {
 128         int n;
 129         FILE * f=NULL;
 130
 131         /* try first here */
 132         if((f=fopen(filename, mode)) != NULL)
 133         {
 134                 add_to_library_path(filename, 1);
 135                 return(f);
 136         }
 137
 138         /* couldn't open; try concatenating all stored paths */
 139         for(n=n_library_paths - 1;n >= 0;n--)
 140         {
 141                 char tmp[4096];
 142
 143                 snprintf(tmp, sizeof(tmp) - 1, "%s/%s",
 144                         library_path[n], filename);
 145                 tmp[sizeof(tmp) - 1]='\0';
 146
 147                 if((f=fopen(tmp, mode)) != NULL)
 148                 {
 149                         add_to_library_path(tmp, 1);
 150                         break;
 151                 }
 152         }
 153
 154         return(f);
 155 }
 156
 157