core: Add 'cat' builtin

2012-03-06 11:59:06 -05:00
1 parent 9dc86d0f5e
commit eb7c3d01a3
@@ -0,0 +1,114 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2011 Colin Walters <walters@verbum.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Colin Walters <walters@verbum.org>
+ */
+
+#include "config.h"
+
+#include "ot-builtins.h"
+#include "ostree.h"
+#include "ostree-repo-file.h"
+
+#include <gio/gunixoutputstream.h>
+#include <glib/gi18n.h>
+
+static GOptionEntry options[] = {
+};
+
+static gboolean
+cat_one_file (GFile         *f,
+              GOutputStream *stdout_stream,
+              GCancellable  *cancellable,
+              GError       **error)
+{
+  gboolean ret = FALSE;
+  GInputStream *in = NULL;
+  
+  if (!ostree_repo_file_ensure_resolved ((OstreeRepoFile*)f, NULL))
+    g_assert_not_reached ();
+
+  in = (GInputStream*)g_file_read (f, cancellable, error);
+  if (!in)
+    goto out;
+
+  if (!g_output_stream_splice (stdout_stream, in, G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE,
+                               cancellable, error))
+    goto out;
+
+  ret = TRUE;
+ out:
+  g_clear_object (&in);
+  return ret;
+}
+
+gboolean
+ostree_builtin_cat (int argc, char **argv, GFile *repo_path, GError **error)
+{
+  GOptionContext *context;
+  gboolean ret = FALSE;
+  OstreeRepo *repo = NULL;
+  int i;
+  GCancellable *cancellable = NULL;
+  const char *rev;
+  GOutputStream *stdout_stream = NULL;
+  GFile *root = NULL;
+  GFile *f = NULL;
+
+  context = g_option_context_new ("COMMIT PATH [PATH...] - Concatenate contents of files");
+  g_option_context_add_main_entries (context, options, NULL);
+
+  if (!g_option_context_parse (context, &argc, &argv, error))
+    goto out;
+
+  repo = ostree_repo_new (repo_path);
+  if (!ostree_repo_check (repo, error))
+    goto out;
+
+  if (argc <= 2)
+    {
+      ot_util_usage_error (context, "An COMMIT and at least one PATH argument are required", error);
+      goto out;
+    }
+  rev = argv[1];
+
+  if (!ostree_repo_read_commit (repo, rev, &root, NULL, error))
+    goto out;
+
+  stdout_stream = g_unix_output_stream_new (1, FALSE);
+
+  for (i = 2; i < argc; i++)
+    {
+      g_clear_object (&f);
+      f = g_file_resolve_relative_path (root, argv[i]);
+
+      if (!cat_one_file (f, stdout_stream, cancellable, error))
+        goto out;
+    }
+ 
+  ret = TRUE;
+ out:
+  g_clear_object (&root);
+  g_clear_object (&f);
+  g_clear_object (&stdout_stream);
+  if (context)
+    g_option_context_free (context);
+  g_clear_object (&repo);
+  return ret;
+}