Use xdg_user_dir_lookup to lookup directories.

chrome/third_party/xdg_user_dirs/xdg_user_dir_lookup.cc

+/*
+  This file is not licenced under the GPL like the rest of the code.
+  Its is under the MIT license, to encourage reuse by cut-and-paste.
+
+  Copyright (c) 2007 Red Hat, inc
+
+  Permission is hereby granted, free of charge, to any person
+  obtaining a copy of this software and associated documentation files
+  (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge,
+  publish, distribute, sublicense, and/or sell copies of the Software,
+  and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions: 
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software. 
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * xdg_user_dir_lookup_with_fallback:
+ * @type: a string specifying the type of directory
+ * @fallback: value to use if the directory isn't specified by the user
+ * @returns: a newly allocated absolute pathname
+ *
+ * Looks up a XDG user directory of the specified type.
+ * Example of types are "DESKTOP" and "DOWNLOAD".
+ *
+ * In case the user hasn't specified any directory for the specified
+ * type the value returned is @fallback.
+ *
+ * The return value is newly allocated and must be freed with
+ * free(). The return value is never NULL if @fallback != NULL, unless
+ * out of memory.
+ **/
+static char *
+xdg_user_dir_lookup_with_fallback (const char *type, const char *fallback)
+{
+  FILE *file;
+  char *home_dir, *config_home, *config_file;
+  char buffer[512];
+  char *user_dir;
+  char *p, *d;
+  int len;
+  int relative;
+  
+  home_dir = getenv ("HOME");
+
+  if (home_dir == NULL)
+    goto error;
+
+  config_home = getenv ("XDG_CONFIG_HOME");
+  if (config_home == NULL || config_home[0] == 0)
+    {
+      config_file = (char*) malloc (strlen (home_dir) + strlen ("/.config/user-dirs.dirs") + 1);
+      if (config_file == NULL)
+        goto error;
+
+      strcpy (config_file, home_dir);
+      strcat (config_file, "/.config/user-dirs.dirs");
+    }
+  else
+    {
+      config_file = (char*) malloc (strlen (config_home) + strlen ("/user-dirs.dirs") + 1);
+      if (config_file == NULL)
+        goto error;
+
+      strcpy (config_file, config_home);
+      strcat (config_file, "/user-dirs.dirs");
+    }
+
+  file = fopen (config_file, "r");
+  free (config_file);
+  if (file == NULL)
+    goto error;
+
+  user_dir = NULL;
+  while (fgets (buffer, sizeof (buffer), file))
+    {
+      /* Remove newline at end */
+      len = strlen (buffer);
+      if (len > 0 && buffer[len-1] == '\n')
+        buffer[len-1] = 0;
+      
+      p = buffer;
+      while (*p == ' ' || *p == '\t')
+        p++;
+      
+      if (strncmp (p, "XDG_", 4) != 0)
+        continue;
+      p += 4;
+      if (strncmp (p, type, strlen (type)) != 0)
+        continue;
+      p += strlen (type);
+      if (strncmp (p, "_DIR", 4) != 0)
+        continue;
+      p += 4;
+
+      while (*p == ' ' || *p == '\t')
+        p++;
+
+      if (*p != '=')
+        continue;
+      p++;
+      
+      while (*p == ' ' || *p == '\t')
+        p++;
+
+      if (*p != '"')
+        continue;
+      p++;
+      
+      relative = 0;
+      if (strncmp (p, "$HOME/", 6) == 0)
+        {
+          p += 6;
+          relative = 1;
+        }
+      else if (*p != '/')
+        continue;
+      
+      if (relative)
+        {
+          user_dir = (char*) malloc (strlen (home_dir) + 1 + strlen (p) + 1);
+          if (user_dir == NULL)
+            goto error2;
+
+          strcpy (user_dir, home_dir);
+          strcat (user_dir, "/");
+        }
+      else
+        {
+          user_dir = (char*) malloc (strlen (p) + 1);
+          if (user_dir == NULL)
+            goto error2;
+
+          *user_dir = 0;
+        }
+      
+      d = user_dir + strlen (user_dir);
+      while (*p && *p != '"')
+        {
+          if ((*p == '\\') && (*(p+1) != 0))
+            p++;
+          *d++ = *p++;
+        }
+      *d = 0;
+    }
+error2:
+  fclose (file);
+
+  if (user_dir)
+    return user_dir;
+
+ error:
+  if (fallback)
+    return strdup (fallback);
+  return NULL;
+}
+
+/**
+ * xdg_user_dir_lookup:
+ * @type: a string specifying the type of directory
+ * @returns: a newly allocated absolute pathname
+ *
+ * Looks up a XDG user directory of the specified type.
+ * Example of types are "DESKTOP" and "DOWNLOAD".
+ *
+ * The return value is always != NULL (unless out of memory),
+ * and if a directory
+ * for the type is not specified by the user the default
+ * is the home directory. Except for DESKTOP which defaults
+ * to ~/Desktop.
+ *
+ * The return value is newly allocated and must be freed with
+ * free().
+ **/
+char *
+xdg_user_dir_lookup (const char *type)
+{
+  char *dir, *home_dir, *user_dir;
+          
+  dir = xdg_user_dir_lookup_with_fallback (type, NULL);
+  if (dir != NULL)
+    return dir;
+  
+  home_dir = getenv ("HOME");
+  
+  if (home_dir == NULL)
+    return strdup ("/tmp");
+  
+  /* Special case desktop for historical compatibility */
+  if (strcmp (type, "DESKTOP") == 0)
+    {
+      user_dir = (char*) malloc (strlen (home_dir) + strlen ("/Desktop") + 1);
+      if (user_dir == NULL)
+        return NULL;
+
+      strcpy (user_dir, home_dir);
+      strcat (user_dir, "/Desktop");
+      return user_dir;
+    }
+  
+  return strdup (home_dir);
+}
+
+#ifdef STANDALONE_XDG_USER_DIR_LOOKUP
+int
+main (int argc, char *argv[])
+{
+  if (argc != 2)
+    {
+      fprintf (stderr, "Usage %s <dir-type>\n", argv[0]);
+      exit (1);
+    }
+  
+  printf ("%s\n", xdg_user_dir_lookup (argv[1]));
+  return 0;
+}
+#endif