New function g_read_link(). (#72545)

* glib/gfileutils.h:
	* glib/gfileutils.c: New function g_read_link(). (#72545)

ChangeLog

@@ -1,5 +1,13 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
+	* glib/gfileutils.h: 
+	* glib/gfileutils.c: New function g_read_link(). (#72545)
+
+	* configure.in: Check for setenv, unsetenv, readlink and symlink.
+
+	* tests/file-test.c (test_readlink): Test for g_read_link() (only on systems supporting
+	symbolic links).
+
 	* tests/env-test.c: New test for g_{get,set,unset}env().
 
 	* tests/Makefile.am (test_programs): Add env-test.

ChangeLog.pre-2-10

@@ -1,5 +1,13 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
+	* glib/gfileutils.h: 
+	* glib/gfileutils.c: New function g_read_link(). (#72545)
+
+	* configure.in: Check for setenv, unsetenv, readlink and symlink.
+
+	* tests/file-test.c (test_readlink): Test for g_read_link() (only on systems supporting
+	symbolic links).
+
 	* tests/env-test.c: New test for g_{get,set,unset}env().
 
 	* tests/Makefile.am (test_programs): Add env-test.

ChangeLog.pre-2-12

@@ -1,5 +1,13 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
+	* glib/gfileutils.h: 
+	* glib/gfileutils.c: New function g_read_link(). (#72545)
+
+	* configure.in: Check for setenv, unsetenv, readlink and symlink.
+
+	* tests/file-test.c (test_readlink): Test for g_read_link() (only on systems supporting
+	symbolic links).
+
 	* tests/env-test.c: New test for g_{get,set,unset}env().
 
 	* tests/Makefile.am (test_programs): Add env-test.

ChangeLog.pre-2-4

@@ -1,5 +1,13 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
+	* glib/gfileutils.h: 
+	* glib/gfileutils.c: New function g_read_link(). (#72545)
+
+	* configure.in: Check for setenv, unsetenv, readlink and symlink.
+
+	* tests/file-test.c (test_readlink): Test for g_read_link() (only on systems supporting
+	symbolic links).
+
 	* tests/env-test.c: New test for g_{get,set,unset}env().
 
 	* tests/Makefile.am (test_programs): Add env-test.

ChangeLog.pre-2-6

@@ -1,5 +1,13 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
+	* glib/gfileutils.h: 
+	* glib/gfileutils.c: New function g_read_link(). (#72545)
+
+	* configure.in: Check for setenv, unsetenv, readlink and symlink.
+
+	* tests/file-test.c (test_readlink): Test for g_read_link() (only on systems supporting
+	symbolic links).
+
 	* tests/env-test.c: New test for g_{get,set,unset}env().
 
 	* tests/Makefile.am (test_programs): Add env-test.

ChangeLog.pre-2-8

@@ -1,5 +1,13 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
+	* glib/gfileutils.h: 
+	* glib/gfileutils.c: New function g_read_link(). (#72545)
+
+	* configure.in: Check for setenv, unsetenv, readlink and symlink.
+
+	* tests/file-test.c (test_readlink): Test for g_read_link() (only on systems supporting
+	symbolic links).
+
 	* tests/env-test.c: New test for g_{get,set,unset}env().
 
 	* tests/Makefile.am (test_programs): Add env-test.

docs/reference/ChangeLog

@@ -1,6 +1,6 @@
 2003-07-28  Matthias Clasen  <maclas@gmx.de>
 
-	* glib/glib-sections.txt: Add g_setenv() and g_unsetenv().  (#100763)
+	* glib/glib-sections.txt: Add g_setenv(), g_unsetenv() and g_read_link().  (#100763, #72545)
 
 2003-07-26  Matthias Clasen  <maclas@gmx.de>
 

docs/reference/glib/glib-sections.txt

@@ -875,6 +875,7 @@ g_file_get_contents
 g_file_test
 g_mkstemp
 g_file_open_tmp
+g_read_link
 
 <SUBSECTION>
 GDir

glib/gfileutils.c

@@ -986,3 +986,62 @@ g_build_filename (const gchar *first_element,
 
   return str;
 }
+
+/**
+ * g_read_link:
+ * @filename: the symbolic link
+ * @error: return location for a #GError
+ *
+ * Reads the contents of the symbolic link @filename like the POSIX readlink() function.
+ * The returned string is in the encoding used for filenames. Use g_filename_to_utf8() to 
+ * convert it to UTF-8.
+ *
+ * Returns: A newly allocated string with the contents of the symbolic link, 
+ *          or %NULL if an error occurred.
+ *
+ * Since: 2.4
+ */
+gchar *
+g_read_link (const gchar *filename,
+	     GError     **error)
+{
+#ifdef HAVE_READLINK
+  gchar *buffer;
+  guint size;
+  gint read_size;    
+  
+  size = 256; 
+  buffer = g_malloc (size);
+  
+  while (TRUE) 
+    {
+      read_size = readlink (filename, buffer, size);
+      if (read_size < 0) {
+	g_free (buffer);
+	g_set_error (error,
+		     G_FILE_ERROR,
+		     g_file_error_from_errno (errno),
+		     _("Failed to read the symbolic link '%s': %s"),
+		     filename, g_strerror (errno));
+	
+	return NULL;
+      }
+    
+      if (read_size < size) 
+	{
+	  buffer[read_size] = 0;
+	  return buffer;
+	}
+      
+      size *= 2;
+      buffer = g_realloc (buffer, size);
+    }
+#else
+  g_set_error (error,
+	       G_FILE_ERROR,
+	       G_FILE_ERROR_INVAL,
+	       _("Symbolic links not supported"));
+	
+  return NULL;
+#endif
+}

glib/gfileutils.h

@@ -78,7 +78,8 @@ gboolean g_file_get_contents (const gchar  *filename,
                               gchar       **contents,
                               gsize        *length,    
                               GError      **error);
-
+gchar * g_read_link          (const gchar  *filename,
+			      GError      **error);
 
 /* Wrapper / workalike for mkstemp() */
 int     g_mkstemp            (char         *tmpl);

tests/file-test.c

@@ -46,7 +46,6 @@ static void
 test_mkstemp (void)
 {
   char template[32];
-  GError *error;
   int fd;
   int i;
   const char hello[] = "Hello, World";
@@ -77,11 +76,61 @@ test_mkstemp (void)
   remove (template);
 }
 
+static void
+test_readlink (void)
+{
+#ifdef HAVE_SYMLINK
+  FILE *file;
+  int result;
+  char *filename = "file-test-data";
+  char *link1 = "file-test-link1";
+  char *link2 = "file-test-link2";
+  char *link3 = "file-test-link3";
+  char *data;
+  GError *error;
+
+  file = fopen (filename, "w");
+  g_assert (file != NULL && "fopen() failed");
+  fclose (file);
+
+  result = symlink (filename, link1);
+  g_assert (result == 0 && "symlink() failed");
+  result = symlink (link1, link2);
+  g_assert (result == 0 && "symlink() failed");
+  
+  error = NULL;
+  data = g_read_link (link1, &error);
+  g_assert (data != NULL && "couldn't read link1");
+  g_assert (strcmp (data, filename) == 0 && "link1 contains wrong data");
+  g_free (data);
+  
+  error = NULL;
+  data = g_read_link (link2, &error);
+  g_assert (data != NULL && "couldn't read link2");
+  g_assert (strcmp (data, link1) == 0 && "link2 contains wrong data");
+  g_free (data);
+  
+  error = NULL;
+  data = g_read_link (link3, &error);
+  g_assert (data == NULL && "could read link3");
+  g_assert (error != NULL && "error not set");
+
+  error = NULL;
+  data = g_read_link (filename, &error);
+  g_assert (data == NULL && "could read regular file as link");
+  g_assert (error != NULL && "error not set");
+  
+  remove (filename);
+  remove (link1);
+  remove (link2);
+#endif
+}
 
 int 
 main (int argc, char *argv[])
 {
   test_mkstemp ();
+  test_readlink ();
 
   return 0;
 }