+#ifndef MAXPATHLEN
+#define MAXPATHLEN 1024
+#endif
+/**
+ * Always return the canonical filename in a newly allocated string
+ */
+char *file_realpath_dup ( const char *path )
+{
+ char real[MAXPATHLEN];
+
+ g_return_val_if_fail(path != NULL, NULL);
+
+ if (file_realpath(path, real))
+ return g_strdup(real);
+
+ return g_strdup(path);
+}
+
+/**
+ * Permission granted to use this code after personal correspondance
+ * Slightly reworked for better cross platform use, glibisms, function rename and a compacter format
+ *
+ * FROM http://www.codeguru.com/cpp/misc/misc/fileanddirectorynaming/article.php/c263
+ */
+
+// GetRelativeFilename(), by Rob Fisher.
+// rfisher@iee.org
+// http://come.to/robfisher
+
+// The number of characters at the start of an absolute filename. e.g. in DOS,
+// absolute filenames start with "X:\" so this value should be 3, in UNIX they start
+// with "\" so this value should be 1.
+#ifdef WINDOWS
+#define ABSOLUTE_NAME_START 3
+#else
+#define ABSOLUTE_NAME_START 1
+#endif
+
+// Given the absolute current directory and an absolute file name, returns a relative file name.
+// For example, if the current directory is C:\foo\bar and the filename C:\foo\whee\text.txt is given,
+// GetRelativeFilename will return ..\whee\text.txt.
+
+const gchar *file_GetRelativeFilename ( gchar *currentDirectory, gchar *absoluteFilename )
+{
+ gint afMarker = 0, rfMarker = 0;
+ gint cdLen = 0, afLen = 0;
+ gint i = 0;
+ gint levels = 0;
+ static gchar relativeFilename[MAXPATHLEN+1];
+
+ cdLen = strlen(currentDirectory);
+ afLen = strlen(absoluteFilename);
+
+ // make sure the names are not too long or too short
+ if (cdLen > MAXPATHLEN || cdLen < ABSOLUTE_NAME_START+1 ||
+ afLen > MAXPATHLEN || afLen < ABSOLUTE_NAME_START+1) {
+ return NULL;
+ }
+
+ // Handle DOS names that are on different drives:
+ if (currentDirectory[0] != absoluteFilename[0]) {
+ // not on the same drive, so only absolute filename will do
+ strcpy(relativeFilename, absoluteFilename);
+ return relativeFilename;
+ }
+
+ // they are on the same drive, find out how much of the current directory
+ // is in the absolute filename
+ i = ABSOLUTE_NAME_START;
+ while (i < afLen && i < cdLen && currentDirectory[i] == absoluteFilename[i]) {
+ i++;
+ }
+
+ if (i == cdLen && (absoluteFilename[i] == G_DIR_SEPARATOR || absoluteFilename[i-1] == G_DIR_SEPARATOR)) {
+ // the whole current directory name is in the file name,
+ // so we just trim off the current directory name to get the
+ // current file name.
+ if (absoluteFilename[i] == G_DIR_SEPARATOR) {
+ // a directory name might have a trailing slash but a relative
+ // file name should not have a leading one...
+ i++;
+ }
+
+ strcpy(relativeFilename, &absoluteFilename[i]);
+ return relativeFilename;
+ }
+
+ // The file is not in a child directory of the current directory, so we
+ // need to step back the appropriate number of parent directories by
+ // using "..\"s. First find out how many levels deeper we are than the
+ // common directory
+ afMarker = i;
+ levels = 1;
+
+ // count the number of directory levels we have to go up to get to the
+ // common directory
+ while (i < cdLen) {
+ i++;
+ if (currentDirectory[i] == G_DIR_SEPARATOR) {
+ // make sure it's not a trailing slash
+ i++;
+ if (currentDirectory[i] != '\0') {
+ levels++;
+ }
+ }
+ }
+
+ // move the absolute filename marker back to the start of the directory name
+ // that it has stopped in.
+ while (afMarker > 0 && absoluteFilename[afMarker-1] != G_DIR_SEPARATOR) {
+ afMarker--;
+ }
+
+ // check that the result will not be too long
+ if (levels * 3 + afLen - afMarker > MAXPATHLEN) {
+ return NULL;
+ }
+
+ // add the appropriate number of "..\"s.
+ rfMarker = 0;
+ for (i = 0; i < levels; i++) {
+ relativeFilename[rfMarker++] = '.';
+ relativeFilename[rfMarker++] = '.';
+ relativeFilename[rfMarker++] = G_DIR_SEPARATOR;
+ }
+
+ // copy the rest of the filename into the result string
+ strcpy(&relativeFilename[rfMarker], &absoluteFilename[afMarker]);
+
+ return relativeFilename;
+}
+/* END http://www.codeguru.com/cpp/misc/misc/fileanddirectorynaming/article.php/c263 */