demo/demo.c

   1 #include "demo.h"
   2 #include <string.h>
   3
   4 /**
   5  * demo_find_data_file:
   6  * @file: the name of a data file
   7  * @caller: caller program (argv[0])
   8  *
   9  * Builds the proper path of a data file, without checking
  10  * for @file existence. This wrapper is needed to allow
  11  * running the program either when uninstalled and installed
  12  * and to deal with different platform issues.
  13  *
  14  * A call is considered coming from an uninstalled program
  15  * if @caller (containing the supposed absolute path of
  16  * the program) contains the LT_OBJDIR constant (usually
  17  * ".libs"), typically used to store an uninstalled binary.
  18  *
  19  * If the call comes from an uninstalled program, @file will
  20  * be searched in the parent directory of @caller dirname.
  21  *
  22  * If the call comes from an installed program, the
  23  * %ADG_DATADIR will be used instead. This constant is set
  24  * by the makefile throught preprocessor flags and will be
  25  * considered an absolute path on non-windows platforms,
  26  * hence resolving to $(pkgdatadir), or a path relative to
  27  * the @caller dirname on windows platforms.
  28  *
  29  * Returns: the full path to @file that must bel freed with
  30  *          g_free() or %NULL on errors
  31  **/
  32 gchar *
  33 demo_find_data_file(const gchar *file, const gchar *caller)
  34 {
  35     static gchar *data_root = NULL;
  36
  37     if (data_root == NULL) {
  38         if (caller == NULL || strstr(caller, LT_OBJDIR) == NULL) {
  39             /* Supposedly, this is a call to an installed program */
  40 #ifdef G_OS_WIN32
  41
  42             /* On windows, ADG_DATADIR is a path relative to the
  43              * caller dirname. This is needed because the data
  44              * files must be relocatable, so the installer is free
  45              * to put the project tree under custom directories.
  46              * Other files, such as headers and libraries, are
  47              * yet properly managed by autotools.
  48              */
  49             gchar *caller_dirname = g_path_get_dirname(caller);
  50             data_root = g_build_filename(caller_dirname, ADG_DATADIR, NULL);
  51             g_free(caller_dirname);
  52
  53 #else /* ! G_OS_WIN32 */
  54
  55             /* On other operating systems, ADG_DATADIR is an
  56              * absolute path, so no further processing is required.
  57              */
  58             data_root = ADG_DATADIR;
  59
  60 #endif
  61         } else {
  62             /* This is likely an uninstalled program call: set
  63              * data_root to the parent directory of the caller dirname.
  64              */
  65             gchar *caller_dirname = g_path_get_dirname(caller);
  66             data_root = g_build_filename(caller_dirname, "..", NULL);
  67             g_free(caller_dirname);
  68         }
  69     }
  70
  71     return g_build_filename(data_root, file, NULL);
  72 }