demo/demo.c

   1 #include "demo.h"
   2
   3 /**
   4  * demo_find_data_file:
   5  * @file: the name of a data file
   6  * @caller: caller program (argv[0])
   7  *
   8  * Builds the proper path of a data file, without checking
   9  * for @file existence. This wrapper is needed to allow
  10  * running the program either when uninstalled and installed
  11  * and to deal with different platform issues.
  12  *
  13  * A call is considered coming from an uninstalled program
  14  * if @caller (containing the supposed absolute path of
  15  * the program) contains the LT_OBJDIR constant (usually
  16  * ".libs"), typically used to store an uninstalled binary.
  17  *
  18  * If the call comes from an uninstalled program, @file will
  19  * be searched in the parent directory of @caller dirname.
  20  *
  21  * If the call comes from an installed program, the
  22  * %ADG_DATADIR will be used instead. This constant is set
  23  * by the makefile throught preprocessor flags and will be
  24  * considered an absolute path on non-windows platforms,
  25  * hence resolving to $(pkgdatadir), or a path relative to
  26  * the @caller dirname on windows platforms.
  27  *
  28  * Returns: the full path to @file that must bel freed with
  29  *          g_free() or %NULL on errors
  30  **/
  31 gchar *
  32 demo_find_data_file(const gchar *file, const gchar *caller)
  33 {
  34     static gchar *data_root = NULL;
  35
  36     if (data_root == NULL) {
  37         if (caller == NULL || strstr(caller, LT_OBJDIR) == NULL) {
  38             /* Supposedly, this is a call to an installed program */
  39 #ifdef G_OS_WIN32
  40
  41             /* On windows, ADG_DATADIR is a path relative to the
  42              * caller dirname. This is needed because the data
  43              * files must be relocatable, so the installer is free
  44              * to put the project tree under custom directories.
  45              * Other files, such as headers and libraries, are
  46              * yet properly managed by autotools.
  47              */
  48             gchar *caller_dirname = g_path_get_dirname(caller);
  49             data_root = g_build_filename(caller_dirname, ADG_DATADIR, NULL);
  50             g_free(caller_dirname);
  51
  52 #else /* ! G_OS_WIN32 */
  53
  54             /* On other operating systems, ADG_DATADIR is an
  55              * absolute path, so no further processing is required.
  56              */
  57             data_root = ADG_DATADIR;
  58
  59 #endif
  60         } else {
  61             /* This is likely an uninstalled program call: set
  62              * data_root to the parent directory of the caller dirname.
  63              */
  64             gchar *caller_dirname = g_path_get_dirname(caller);
  65             data_root = g_build_filename(caller_dirname, "..", NULL);
  66             g_free(caller_dirname);
  67         }
  68     }
  69
  70     return g_build_filename(data_root, file, NULL);
  71 }