[PATCH 1/2] cli: add mechanism for running user configurable hooks

[Jani Nikula]

Add support functions for running hooks configurable in the notmuch config
file. The hooks will be run using system(1).

TODO:

* Move notmuch_run_hook() out of notmuch-new.c. It's there and static only
  because the first user will be there.

* Consider merging this with the following patch, as this is slightly
  artificial as it is.

Signed-off-by: Jani Nikula <jani at nikula.org>
---
 notmuch-client.h |    7 +++++++
 notmuch-config.c |   21 +++++++++++++++++++++
 notmuch-new.c    |   25 +++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/notmuch-client.h b/notmuch-client.h
index b50cb38..5e2fed2 100644
--- a/notmuch-client.h
+++ b/notmuch-client.h
@@ -87,6 +87,10 @@ typedef struct notmuch_show_params {
     int decrypt;
 } notmuch_show_params_t;
 
+typedef enum {
+    NOTMUCH_HOOK_PLACEHOLDER,
+} notmuch_hook_t;
+
 /* There's no point in continuing when we've detected that we've done
  * something wrong internally (as opposed to the user passing in a
  * bogus value).
@@ -235,6 +239,9 @@ void
 notmuch_config_set_maildir_synchronize_flags (notmuch_config_t *config,
 					      notmuch_bool_t synchronize_flags);
 
+const char *
+notmuch_config_get_hook (notmuch_config_t *config, notmuch_hook_t hook);
+
 notmuch_bool_t
 debugger_is_active (void);
 
diff --git a/notmuch-config.c b/notmuch-config.c
index 1a7ed58..8f1a038 100644
--- a/notmuch-config.c
+++ b/notmuch-config.c
@@ -608,6 +608,27 @@ notmuch_config_set_new_tags (notmuch_config_t *config,
     config->new_tags = NULL;
 }
 
+const char *
+notmuch_config_get_hook (notmuch_config_t *config, notmuch_hook_t hook)
+{
+    char *command;
+    const char *group, *key;
+
+    switch (hook) {
+    default:
+	INTERNAL_ERROR ("Unknown hook %d\n.", hook);
+    }
+
+    command = g_key_file_get_string (config->key_file, group, key, NULL);
+    if (command) {
+	char *p = command;
+	command = talloc_strdup (config, command);
+	free (p);
+    }
+
+    return command;
+}
+
 /* Given a configuration item of the form <group>.<key> return the
  * component group and key. If any error occurs, print a message on
  * stderr and return 1. Otherwise, return 0.
diff --git a/notmuch-new.c b/notmuch-new.c
index 81a9350..0c70e64 100644
--- a/notmuch-new.c
+++ b/notmuch-new.c
@@ -795,6 +795,31 @@ _remove_directory (void *ctx,
     notmuch_directory_destroy (directory);
 }
 
+static int
+notmuch_run_hook (notmuch_config_t *config, notmuch_hook_t hook)
+{
+    const char *command;
+    int r;
+
+    command = notmuch_config_get_hook (config, hook);
+    if (!command)
+	return NOTMUCH_STATUS_SUCCESS; /* It's okay not to have a hook */
+
+    r = system(command);
+    if (r) {
+	if (WIFSIGNALED(r))
+	    fprintf(stderr, "hook '%s' terminated with signal %d\n",
+		    command, WTERMSIG(r));
+	else
+	    fprintf(stderr, "hook '%s' failed with status %d\n",
+		    command, WEXITSTATUS(r));
+
+	r = NOTMUCH_STATUS_FILE_ERROR; /* FIXME */
+    }
+
+    return r;
+}
+
 int
 notmuch_new_command (void *ctx, int argc, char *argv[])
 {
-- 
1.7.5.4