[gnome-software] Add two utility functions for plugins

[Richard Hughes <rhughes src gnome org>]

commit 4c59a3edc7d597cf7b8135b5ee5643dfb564c5f0
Author: Richard Hughes <richard hughsie com>
Date:   Tue Jun 7 15:21:15 2016 +0100

    Add two utility functions for plugins

 src/gs-utils.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/gs-utils.h |    5 +++++
 2 files changed, 56 insertions(+), 0 deletions(-)
---
diff --git a/src/gs-utils.c b/src/gs-utils.c
index 12d03ea..08430f5 100644
--- a/src/gs-utils.c
+++ b/src/gs-utils.c
@@ -34,6 +34,7 @@
 
 #include <errno.h>
 #include <fnmatch.h>
+#include <glib/gstdio.h>
 
 #ifdef HAVE_POLKIT
 #include <polkit/polkit.h>
@@ -306,4 +307,54 @@ gs_utils_get_desktop_app_info (const gchar *id)
        return app_info;
 }
 
+/**
+ * gs_utils_symlink:
+ * @target: the full path of the symlink to create
+ * @source: where the symlink should point to
+ * @error: A #GError, or %NULL
+ *
+ * Creates a symlink that can cross filesystem boundaries.
+ * Any parent directories needed for target to exist are also created.
+ *
+ * Returns: %TRUE for success
+ **/
+gboolean
+gs_utils_symlink (const gchar *target, const gchar *linkpath, GError **error)
+{
+       if (!gs_mkdir_parent (target, error))
+               return FALSE;
+       if (symlink (target, linkpath) != 0) {
+               g_set_error (error,
+                            GS_PLUGIN_ERROR,
+                            GS_PLUGIN_ERROR_FAILED,
+                            "failed to create symlink from %s to %s",
+                            linkpath, target);
+               return FALSE;
+       }
+       return TRUE;
+}
+
+/**
+ * gs_utils_unlink:
+ * @filename: A full pathname to delete
+ * @error: A #GError, or %NULL
+ *
+ * Deletes a file from disk.
+ *
+ * Returns: %TRUE for success
+ **/
+gboolean
+gs_utils_unlink (const gchar *filename, GError **error)
+{
+       if (g_unlink (filename) != 0) {
+               g_set_error (error,
+                            GS_PLUGIN_ERROR,
+                            GS_PLUGIN_ERROR_FAILED,
+                            "failed to delete %s",
+                            filename);
+               return FALSE;
+       }
+       return TRUE;
+}
+
 /* vim: set noexpandtab: */
diff --git a/src/gs-utils.h b/src/gs-utils.h
index ee55388..8fd1f3d 100644
--- a/src/gs-utils.h
+++ b/src/gs-utils.h
@@ -47,6 +47,11 @@ guint                 gs_utils_get_file_age          (GFile          *file);
 gchar          *gs_utils_get_content_type      (GFile          *file,
                                                 GCancellable   *cancellable,
                                                 GError         **error);
+gboolean        gs_utils_symlink               (const gchar    *target,
+                                                const gchar    *linkpath,
+                                                GError         **error);
+gboolean        gs_utils_unlink                (const gchar    *filename,
+                                                GError         **error);
 gboolean        gs_mkdir_parent                (const gchar    *path,
                                                 GError         **error);
 gchar          *gs_utils_get_cache_filename    (const gchar    *kind,