Support for non-builtin commands

[Stef Walter <stefw gnome org>]

So while waiting for ostree-pull (it's still going :), I put together
this patch so that you can run 'ostree pull' instead of 'ostree-pull'.

What do you think?

Stef

>From 66c8a1d3f6d3170193fd26977981291756f37210 Mon Sep 17 00:00:00 2001
From: Stef Walter <stefw gnome org>
Date: Fri, 10 Aug 2012 15:55:26 +0200
Subject: [PATCH] Support non-builtin commands

 * Support executing commands in the path
 * This makes 'ostree-pull' work as 'ostree pull'
---
 src/ostree/main.c    | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/ostree/ot-main.c | 51 +++++++++++++++++++++++++++++++----------------
 src/ostree/ot-main.h |  3 +++
 3 files changed, 92 insertions(+), 18 deletions(-)

diff --git a/src/ostree/main.c b/src/ostree/main.c
index e1218f0..5d7260f 100644
--- a/src/ostree/main.c
+++ b/src/ostree/main.c
@@ -24,6 +24,7 @@
 
 #include <gio/gio.h>
 
+#include <errno.h>
 #include <string.h>
 
 #include "ot-main.h"
@@ -52,9 +53,62 @@ static OstreeBuiltin builtins[] = {
   { NULL }
 };
 
+static int
+exec_external (int      argc,
+               char   **argv,
+               GError **error)
+{
+  gchar *command;
+  gchar *tmp;
+  int errn;
+
+  command = g_strdup_printf ("ostree-%s", argv[1]);
+
+  tmp = argv[1];
+  argv[1] = command;
+
+  execvp (command, argv + 1);
+
+  errn = errno;
+  argv[1] = tmp;
+  g_free (command);
+
+  if (errn == ENOENT)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                   "Unknown command: '%s'", argv[1]);
+    }
+  else
+    {
+      g_set_error (error, G_FILE_ERROR, g_file_error_from_errno (errn),
+                   "Failed to execute command: %s", g_strerror (errn));
+    }
+
+  return 1;
+}
+
 int
 main (int    argc,
       char **argv)
 {
-  return ostree_main (argc, argv, builtins);
+  GError *error = NULL;
+  int ret;
+
+  ret = ostree_run (argc, argv, builtins, &error);
+  if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
+    {
+      g_clear_error (&error);
+      ret = exec_external (argc, argv, &error);
+    }
+
+  if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
+    ostree_usage (argv, builtins, TRUE);
+
+  if (error != NULL)
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+    }
+
+  return ret;
 }
diff --git a/src/ostree/ot-main.c b/src/ostree/ot-main.c
index 85f39ab..2f64fc5 100644
--- a/src/ostree/ot-main.c
+++ b/src/ostree/ot-main.c
@@ -29,8 +29,8 @@
 #include "ot-main.h"
 #include "otutil.h"
 
-static int
-usage (char **argv, OstreeBuiltin *builtins, gboolean is_error)
+int
+ostree_usage (char **argv, OstreeBuiltin *builtins, gboolean is_error)
 {
   OstreeBuiltin *builtin = builtins;
   void (*print_func) (const gchar *format, ...);
@@ -72,17 +72,11 @@ prep_builtin_argv (const char *builtin,
   *out_argv = cmd_argv;
 }
 
-static void
-set_error_print_usage (GError **error, OstreeBuiltin *builtins, const char *msg, char **argv)
-{
-  g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED, msg);
-  usage (argv, builtins, TRUE);
-}
-
 int
-ostree_main (int    argc,
-             char **argv,
-             OstreeBuiltin  *builtins)
+ostree_run (int    argc,
+            char **argv,
+            OstreeBuiltin  *builtins,
+            GError **res_error)
 {
   OstreeBuiltin *builtin;
   GError *error = NULL;
@@ -105,7 +99,7 @@ ostree_main (int    argc,
   g_set_prgname (argv[0]);
 
   if (argc < 2)
-    return usage (argv, builtins, 1);
+    return ostree_usage (argv, builtins, 1);
 
   am_root = getuid () == 0;
   have_repo_arg = g_str_has_prefix (argv[1], "--repo=");
@@ -157,13 +151,15 @@ ostree_main (int    argc,
   if (!builtin->name)
     {
       ot_lfree char *msg = g_strdup_printf ("Unknown command '%s'", cmd);
-      set_error_print_usage (&error, builtins, msg, argv);
+      g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, msg);
       goto out;
     }
 
   if (repo == NULL && !(builtin->flags & OSTREE_BUILTIN_FLAG_NO_REPO))
     {
-      set_error_print_usage (&error, builtins, "Command requires a --repo argument", argv);
+      g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                           "Command requires a --repo argument");
+      ostree_usage (argv, builtins, TRUE);
       goto out;
     }
   
@@ -177,9 +173,30 @@ ostree_main (int    argc,
   g_clear_object (&repo_file);
   if (error)
     {
-      g_printerr ("%s\n", error->message);
-      g_clear_error (&error);
+      g_propagate_error (res_error, error);
       return 1;
     }
   return 0;
 }
+
+int
+ostree_main (int    argc,
+             char **argv,
+             OstreeBuiltin  *builtins)
+{
+  GError *error = NULL;
+  int ret;
+
+  ret = ostree_run (argc, argv, builtins, &error);
+
+  if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
+    ostree_usage (argv, builtins, TRUE);
+
+  if (error)
+    {
+      g_printerr ("%s\n", error->message);
+      g_error_free (error);
+    }
+
+  return ret;
+}
diff --git a/src/ostree/ot-main.h b/src/ostree/ot-main.h
index 34142cf..7712db1 100644
--- a/src/ostree/ot-main.h
+++ b/src/ostree/ot-main.h
@@ -35,3 +35,6 @@ typedef struct {
 
 int ostree_main (int    argc, char **argv, OstreeBuiltin  *builtins);
 
+int ostree_run (int    argc, char **argv, OstreeBuiltin  *builtins, GError **error);
+
+int ostree_usage (char **argv, OstreeBuiltin *builtins, gboolean is_error);
-- 
1.7.11.4