1 files changed, 113 insertions, 0 deletions
diff --git a/src/hooks.c b/src/hooks.c
new file mode 100644
index 0000000..d051c4b
--- /dev/null
+++ b/src/hooks.c
@@ -0,0 +1,113 @@
+/* hooks.c -- Hooks triggered by events
+   This file is part of Redshift.
+
+   Redshift is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Redshift 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Redshift.  If not, see <http://www.gnu.org/licenses/>.
+
+   Copyright (c) 2014  Jon Lund Steffensen <jonlst@gmail.com>
+*/
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <errno.h>
+#ifndef _WIN32
+# include <pwd.h>
+#endif
+
+#include "hooks.h"
+#include "redshift.h"
+
+#define MAX_HOOK_PATH  4096
+
+
+/* Names of periods supplied to scripts. */
+static const char *period_names[] = {
+	"none",
+	"daytime",
+	"night",
+	"transition"
+};
+
+
+/* Try to open the directory containing hooks. HP is a string
+   of MAX_HOOK_PATH length that will be filled with the path
+   of the returned directory. */
+static DIR *
+open_hooks_dir(char *hp)
+{
+	char *env;
+
+	if ((env = getenv("XDG_CONFIG_HOME")) != NULL &&
+	    env[0] != '\0') {
+		snprintf(hp, MAX_HOOK_PATH, "%s/redshift/hooks", env);
+		return opendir(hp);
+	}
+
+	if ((env = getenv("HOME")) != NULL &&
+	    env[0] != '\0') {
+		snprintf(hp, MAX_HOOK_PATH, "%s/.config/redshift/hooks", env);
+		return opendir(hp);
+	}
+
+#ifndef _WIN32
+	struct passwd *pwd = getpwuid(getuid());
+	snprintf(hp, MAX_HOOK_PATH, "%s/.config/redshift/hooks", pwd->pw_dir);
+	return opendir(hp);
+#else
+	return NULL;
+#endif
+}
+
+/* Run hooks with a signal that the period changed. */
+void
+hooks_signal_period_change(period_t prev_period, period_t period)
+{
+	char hooksdir_path[MAX_HOOK_PATH];
+	DIR *hooks_dir = open_hooks_dir(hooksdir_path);
+	if (hooks_dir == NULL) return;
+
+	struct dirent* ent;
+	while ((ent = readdir(hooks_dir)) != NULL) {
+		/* Skip hidden and special files (., ..) */
+		if (ent->d_name[0] == '\0' || ent->d_name[0] == '.') continue;
+
+		char *hook_name = ent->d_name;
+		char hook_path[MAX_HOOK_PATH];
+		snprintf(hook_path, sizeof(hook_path), "%s/%s",
+			 hooksdir_path, hook_name);
+
+#ifndef _WIN32
+		/* Fork and exec the hook. We close stdout
+		   so the hook cannot interfere with the normal
+		   output. */
+		pid_t pid = fork();
+		if (pid == (pid_t)-1) {
+			perror("fork");
+			continue;
+		} else if (pid == 0) { /* Child */
+			close(STDOUT_FILENO);
+
+			int r = execl(hook_path, hook_name,
+				      "period-changed",
+				      period_names[prev_period],
+				      period_names[period], NULL);
+			if (r < 0 && errno != EACCES) perror("execl");
+
+			/* Only reached on error */
+			_exit(EXIT_FAILURE);
+		}
+#endif
+	}
+}