Add support for specifying hook file

Signed-off-by: Mattias Andrée <m@maandree.se>

8 files changed, 230 insertions, 41 deletions

diff --git a/README b/README
index 994c8bf..3b04e0b 100644
--- a/README
+++ b/README
@@ -9,7 +9,7 @@ NAME
 
 SYNOPSIS
 	redshift [-b brightness] [-c config-file] [-D | +D]
-	         [-E | +E | -e elevations] [-g gamma]
+	         [-E | +E | -e elevations] [-g gamma] [-H hook-file]
 	         [-l latitude:longitude | -l provider[:options]]
 	         [-m method[:options]] [-P | +P] [-r | +r] [-dv]
 	         [-O temperature | -o | -p | -t temperature | -x] | -h | -V
@@ -123,6 +123,12 @@ OPTIONS
 		nothing is omitted or an entire set, including its two colons
 		(:) are omitted.
 
+	-H hook-file
+		Select hook file or directory.
+
+		/dev/null or /var/empty can be used to tell redshift not to run
+		hook files.
+
 	-h
 		Display help message.
 
@@ -531,6 +537,13 @@ EXTENDED DESCRIPTION
 		however if only one value is specified it is applied to all
 		each channels.
 
+	hook = file or directory
+		Set hook file or directory. If not specified, the default
+		paths are searched.
+
+		/dev/null and /var/empty can be used to prevent redshift from
+		executing hooks.
+
 	fade = 0 or 1
 		Disable (if 0) or enable (if 1) fading between colour settings
 		with large differences.
diff --git a/TODO b/TODO
index 6f2b898..ad92741 100644
--- a/TODO
+++ b/TODO
@@ -93,15 +93,14 @@ https://github.com/jonls/redshift/issues/31	Change temperature from the icon
 https://github.com/jonls/redshift/issues/629	add option to switch between profiles
 https://github.com/jonls/redshift/issues/347	Support Wingpanel API
 
-Add -H for hook file/directory, support /var/empty on all platforms (should always disable hooks even if that directory isn't actually empty)
 po/sv.po: lost -> förlorad -> försvunnen
 po/de.po: lost -> verloren -> verschwunden
 po/sv.po: felaktig -> ogiltig (?)
 Optionally use METAR data adjust day-time colour temperature according the cloudiness
 read the monitor's chromas to determine it's colour space and correct the RGB multipliers according
-Use coordinates (zone1970.tab, be aware that the coordinates are store in degress and minutes, and sometimes also seconds, not degrees with decimals), for the user's timezone, from tzdata as a fallback
 Add support for solar time.
 When disabled, redshift should be periodically set the gamma ramps
 Add signals for setting location
 Add signals for responding with sigqueue the state of redshift
 print, for use by frontends, what mode redshift was started in
+[Windows] Make sure extended paths are supported
diff --git a/redshift.1 b/redshift.1
index b978f1f..33706fc 100644
--- a/redshift.1
+++ b/redshift.1
@@ -12,6 +12,8 @@ redshift \- Automatically adjust display colour temperature according the Sun
 .IR elevations ]
 [-g
 .IR gamma ]
+[-H
+.IR hook-file ]
 [-l
 .IB latitude : longitude
 | -l
@@ -179,6 +181,14 @@ nothing is omitted or an entire set, including its two colons
 .RB ( : )
 are omitted.
 .TP
+.BI -H\fR\  hook-file
+Select hook file or directory.
+
+.B /dev/null
+or
+.B /var/empty
+can be used to tell redshift not to run hook files.
+.TP
 .B -h
 Display help message.
 .TP
@@ -840,6 +850,15 @@ Set gamma correction for nighttime. Values must be within [0.1,
 however if only one value is specified it is applied to all
 each channels.
 .TP
+.BI hook\fR\ =\  "file or directory"
+Set hook file or directory. If not specified, the default
+paths are searched.
+
+.B /dev/null
+and
+.B /var/empty
+can be used to prevent redshift from executing hooks.
+.TP
 .BI fade\fR\ =\ \fP0 " or " 1
 Disable (if
 .BR 0 )
diff --git a/src/common.h b/src/common.h
index f5be542..61e5c79 100644
--- a/src/common.h
+++ b/src/common.h
@@ -738,6 +738,14 @@ struct setting_time {
 };
 
 /**
+ * `char *` valued setting with setting source
+ */
+struct setting_str {
+	enum setting_source source; /**< Setting source */
+	char *value;                /**< Setting value */
+};
+
+/**
  * Intermediate settings representation of colour settings
  * (for a non-transitional period) with settings sources
  * used for determining whether settings from the configuration
@@ -807,6 +815,14 @@ struct settings {
 	int until_death;
 
 	/**
+	 * The path to the hook file or hook directory, `NULL`
+	 * if unspecified (search default paths)
+	 * 
+	 * This represents the "hook" setting and "-H" option
+	 */
+	struct setting_str hook_file;
+
+	/**
 	 * Whether the program should preserve preapplied
 	 * colour calibrations
 	 * 
@@ -1183,6 +1199,12 @@ extern int use_fade;
  */
 extern int verbose;
 
+/**
+ * The path to the hook file or hook directory, `NULL`
+ * if unspecified (search default paths)
+ */
+extern char *hook_file;
+
 
 /* backend-direct.c */
 
@@ -1357,11 +1379,14 @@ LIST_RAMPS_STOP_VALUE_TYPES(X, ;);
 /**
  * Load the configuration file
  * 
- * @param  state  Output parameter for the configurations
- * @param  path   The path to the configuration file, or `NULL` if the
- *                application should look for it in the default paths
- */
-void config_ini_init(struct config_ini_state *state, const char *path);
+ * @param   state        Output parameter for the configurations
+ * @param   path         The path to the configuration file, or `NULL` if the
+ *                       application should look for it in the default paths
+ * @param   pathbuf_out  Output parameter for the memory allocated for the
+ *                       return value
+ * @return               The path to the loaded configuration file, `NULL` if none
+ */
+const char *config_ini_init(struct config_ini_state *state, const char *path, char **pathbuf_out);
 
 /**
  * Deallocate the settings loaded
diff --git a/src/config-ini.c b/src/config-ini.c
index d5056dc..13aaa57 100644
--- a/src/config-ini.c
+++ b/src/config-ini.c
@@ -146,12 +146,12 @@ open_config_file(const char *path, const char **path_out, char **pathbuf_out, in
 }
 
 
-void
-config_ini_init(struct config_ini_state *state, const char *path)
+const char *
+config_ini_init(struct config_ini_state *state, const char *path, char **pathbuf_out)
 {
 	struct config_ini_section *section = NULL;
 	struct config_ini_setting *setting;
-	char *line = NULL, *s, *p, *value, *end, *pathbuf;
+	char *line = NULL, *s, *p, *value, *end;
 	char *next_line = NULL, *name;
 	size_t size = 0;
 	ssize_t len = 0; /* initialised to silence false warning from clang */
@@ -159,10 +159,11 @@ config_ini_init(struct config_ini_state *state, const char *path)
 	int should_close;
 
 	state->sections = NULL;
+	*pathbuf_out = NULL;
 
-	f = open_config_file(path, &path, &pathbuf, &should_close);
+	f = open_config_file(path, &path, pathbuf_out, &should_close);
 	if (!f)
-		return;
+		return NULL;
 
 #ifndef WINDOWS
 again:
@@ -227,10 +228,11 @@ again:
 		eprintf("getline %s:", path);
 	}
 
-	free(pathbuf);
 	free(line);
 	if (should_close)
 		fclose(f);
+
+	return path;
 }
 
 
diff --git a/src/config.c b/src/config.c
index 7843c08..29c5a53 100644
--- a/src/config.c
+++ b/src/config.c
@@ -30,7 +30,7 @@ usage_no_exit(FILE *f)
 {
 	fprintf(f, _("Usage: %s %s\n"), argv0,
 	        _("[-b brightness] [-c config-file] [-D | +D] [-E | +E | -e elevations] "
-	          "[-g gamma] [-l latitude:longitude | -l provider[:options]] "
+	          "[-g gamma] [-H hook-file] [-l latitude:longitude | -l provider[:options]] "
 	          "[-m method[:options]] [-P | +P] [-r | +r] [-dv] "
 	          "[-O temperature | -o | -p | -t temperature | -x] | -h | -V"));
 }
@@ -54,6 +54,7 @@ enum program_mode mode = PROGRAM_MODE_CONTINUAL;
 int preserve_gamma;
 int use_fade;
 int verbose = 0;
+char *hook_file;
 
 
 /**
@@ -78,6 +79,7 @@ print_help(void)
 	printf(_("  -e day:night             Select solar elevation thresholds for day and night (Default: %g:%g)\n"),
 	                                     DEFAULT_HIGH_ELEVATION, DEFAULT_LOW_ELEVATION);
 	printf(_("  -g day:night             Additional gamma correction (Default: 1:1:1:1:1:1)\n"));
+	printf(_("  -H hook-file             Select hook file or directrory\n"));
 	printf(_("  -h                       Display this help message\n"));
 	printf(_("  -l lat:lon               Specific geographical location\n"));
 	printf(_("  -l provider[:options]    Select location provider to get geographical location\n"));
@@ -657,6 +659,7 @@ load_defaults(struct settings *settings)
 	settings->night.gamma.value[1] = DEFAULT_NIGHT_GAMMA;
 	settings->night.gamma.value[2] = DEFAULT_NIGHT_GAMMA;
 
+	settings->hook_file.value = NULL;
 	settings->preserve_gamma.value = 1;
 	settings->use_fade.value = 1;
 
@@ -716,6 +719,12 @@ load_from_cmdline(struct settings *settings, int argc, char *argv[])
 		set_gamma(ARG(), &settings->day.gamma, &settings->night.gamma, NULL);
 		break;
 
+	case 'H':
+		settings->hook_file.source |= SETTING_CMDLINE;
+		free(settings->hook_file.value);
+		settings->hook_file.value = ARG();
+		break;
+
 	case 'h':
 		print_help();
 		exit(0);
@@ -899,6 +908,15 @@ load_from_config_ini(struct settings *settings, const char *key, char *value)
 		if (settings->use_fade.source <= SETTING_CONFIGFILE)
 			settings->use_fade.value = get_boolean(value, key);
 
+	} else if (!strcasecmp(key, "hook")) {
+		if (settings->hook_file.source & SETTING_CONFIGFILE)
+			weprintf(_("`hook' setting specified multiple times in configuration file."));
+		settings->hook_file.source |= SETTING_CONFIGFILE;
+		if (settings->hook_file.source <= SETTING_CONFIGFILE) {
+			free(settings->hook_file.value);
+			settings->hook_file.value = estrdup(value);
+		}
+
 	} else if (!strcasecmp(key, "preserve-gamma")) {
 		if (settings->preserve_gamma.source & SETTING_CONFIGFILE)
 			weprintf(_("`preserve-gamma' setting specified multiple times in configuration file."));
@@ -955,8 +973,11 @@ load_settings(struct settings *settings, int argc, char *argv[])
 	struct config_ini_section *section;
 	struct config_ini_setting *setting;
 	const struct time_period *first, *current;
+	const char *conf_path, *p;
+	char *conf_pathbuf, *s;
 	int i, j, n;
 	time_t duration;
+	size_t len;
 
 	/* Clear unused bit so they do not interfere with comparsion */
 	memset(&day_settings, 0, sizeof(day_settings));
@@ -965,7 +986,7 @@ load_settings(struct settings *settings, int argc, char *argv[])
 	/* Load settings; some validation takes place */
 	load_defaults(settings);
 	load_from_cmdline(settings, argc, argv);
-	config_ini_init(&settings->config, settings->config_file);
+	conf_path = config_ini_init(&settings->config, settings->config_file, &conf_pathbuf);
 	if ((section = config_ini_get_section(&settings->config, "redshift")))
 		for (setting = section->settings; setting; setting = setting->next)
 			load_from_config_ini(settings, setting->name, setting->value);
@@ -1014,9 +1035,67 @@ load_settings(struct settings *settings, int argc, char *argv[])
 		goto settings_published;
 	}
 
+	/* Make hook file absolute if set from config file (relative to config file) */
+	if (settings->hook_file.source == SETTING_CONFIGFILE && conf_path) {
+#ifdef WINDOWS
+		/* Regular absolute path */
+		if (isalpha(settings->hook_file.value[0]) && settings->hook_file.value[1] == ':')
+			goto absolute_hook_path;
+		/* Absolute extended path or network path (relative extended paths do not exist) */
+		if (settings->hook_file.value[0] == '\\' && settings->hook_file.value[1] == '\\')
+			goto absolute_hook_path;
+		/* Path relative to root */
+		if (settings->hook_file.value[0] == '\\' || settings->hook_file.value[0] == '/') {
+			/* This is safe as we know that `conf_path` is a valid path */
+			if (isalpha(conf_path[0]) && conf_path[1] == ':') {
+				p = &conf_path[3];
+				goto base_found;
+			} else if (conf_path[0] == '\\' && conf_path[1] == '\\') {
+				p = &conf_path[2];
+				while (*p == '\\')
+					p++;
+				while (*p != '/' && *p != '\\')
+					p++;
+				goto base_found;
+			}
+		}
+#else
+		if (settings->hook_file.value[0] == '/')
+			goto absolute_hook_path;
+#endif
+		p = strrchr(conf_path, '/');
+		p = p ? &p[1] : conf_path;
+#ifdef WINDOWS
+		if (strrchr(p, '\\'))
+			p = &strrchr(p, '\\')[1];
+	base_found:
+#endif
+		len = (size_t)(p - conf_path);
+		s = emalloc(len + strlen(settings->hook_file.value) + 1U);
+		memcpy(s, conf_path, len);
+		stpcpy(&s[len], settings->hook_file.value);
+		free(settings->hook_file.value);
+		settings->hook_file.value = s;
+#ifdef WINDOWS
+		/* Used extended path is too long */
+		if (settings->hook_file.value[0] != '\\' && (len = strlen(settings->hook_file.value)) >= 260) {
+			/* We have already made sure the path is absolute, so \ prefix is always extended or network path */
+			settings->hook_file.value = erealloc(settings->hook_file.value, len + sizeof("\\\\?\\"));
+			memmove(&settings->hook_file.value[4], &settings->hook_file.value, len + 1U);
+			settings->hook_file.value[0] = '\\';
+			settings->hook_file.value[1] = '\\';
+			settings->hook_file.value[2] = '?';
+			settings->hook_file.value[3] = '\\';
+		}
+#endif
+	}
+	free(conf_pathbuf);
+absolute_hook_path:
+
 	/* Publish loaded settings */
 	if (mode == PROGRAM_MODE_ONE_SHOT && settings->until_death)
 		mode = PROGRAM_MODE_UNTIL_DEATH;
+	hook_file = settings->hook_file.value, settings->hook_file.value = NULL;
 	preserve_gamma = settings->preserve_gamma.value;
 	use_fade = settings->use_fade.value;
 	disable ^= settings->disabled.value;
diff --git a/src/hooks.c b/src/hooks.c
index be02b18..96f6f83 100644
--- a/src/hooks.c
+++ b/src/hooks.c
@@ -111,6 +111,45 @@ open_hooks_dir(const char **path_out, char **pathbuf_out)
 
 
 /**
+ * Run hook file
+ *
+ * @param  path  The path to the hook file
+ * @param  argv  `NULL` terminated list of command line arguments
+ *               for the hooks; must contain an unused initial slot,
+ *               which the function will use to provide the zeroth
+ *               argument
+ */
+static void
+run_hook(const char *path, const char *argv[])
+{
+#ifdef WINDOWS
+	/* TODO [Windows] hooks are not support on Windows */
+#else
+	switch (fork()) {
+	case -1:
+		weprintf("fork:");
+		break;
+
+	case 0:
+		if (dup2(STDOUT_FILENO, STDERR_FILENO) != STDERR_FILENO) {
+			weprintf("dup2 <stdout> <stderr>:");
+			_exit(1);
+		}
+		argv[0] = path;
+		execv(path, (const void *)argv);
+		if (errno != EACCES)
+			weprintf("execv %s:", path);
+		_exit(1);
+
+	default:
+		/* SIGCHLD is ignored */
+		break;
+	}
+#endif
+}
+
+
+/**
  * Run hooks
  *
  * @param  argv  `NULL` terminated list of command line arguments
@@ -122,13 +161,44 @@ static void
 run_hooks(const char *argv[])
 {
 	static int looked_up_dir = 0;
+	static int hook_file_is_regular = 0;
+	static int hook_file_checked = 0;
 
 	DIR *dir;
 	struct dirent *f;
 	size_t required;
 	const char *dirpath_static;
 
-	if (!looked_up_dir) {
+	if (hook_file_is_regular) {
+		goto run_hook_file;
+
+	} else if (hook_file) {
+		if (!hook_file_checked) {
+			hook_file_checked = 1;
+			if (!strcmp(hook_file, "/dev/null") ||
+			    !strcmp(hook_file, "/var/empty") ||
+			    !strcmp(hook_file, "/var/empty/"))
+				    goto no_hooks;
+		}
+
+		dir = opendir(hook_file);
+		if (!dir) {
+			if (errno == ENOTDIR) {
+				hook_file_is_regular = 1;
+			run_hook_file:
+				run_hook(hook_file, argv);
+				return;
+			}
+			weprintf("opendir %s:", hook_file);
+		no_hooks:
+			free(hook_file);
+			hook_file = NULL;
+			looked_up_dir = 1;
+			dirpath = NULL;
+			return;
+		}
+
+	} else if (!looked_up_dir) {
 		looked_up_dir = 1;
 		dir = open_hooks_dir(&dirpath_static, &dirpath);
 		if (!dir)
@@ -137,6 +207,7 @@ run_hooks(const char *argv[])
 			dirpath = estrdup(dirpath_static);
 		dirpathsize = dirpathlen = strlen(dirpath);
 		atexit(&cleanup);
+
 	} else if (dirpath) {
 		dir = opendir(dirpath);
 		if (!dir) {
@@ -144,6 +215,7 @@ run_hooks(const char *argv[])
 			cleanup();
 			return;
 		}
+
 	} else {
 		return;
 	}
@@ -155,32 +227,11 @@ run_hooks(const char *argv[])
 		required = dirpathlen + sizeof("/") + strlen(f->d_name);
 		if (required > dirpathsize)
 			dirpath = erealloc(dirpath, dirpathsize = required);
+		stpcpy(stpcpy(&dirpath[dirpathlen], "/"), f->d_name);
 
-#ifdef WINDOWS
-		/* TODO [Windows] hooks are not support on Windows */
-#else
-		switch (fork()) {
-		case -1:
-			weprintf("fork:");
-			break;
-
-		case 0:
-			if (dup2(STDOUT_FILENO, STDERR_FILENO) != STDERR_FILENO) {
-				weprintf("dup2 <stdout> <stderr>:");
-				_exit(1);
-			}
-			stpcpy(stpcpy(&dirpath[dirpathlen], "/"), f->d_name);
-			argv[0] = dirpath;
-			execv(dirpath, (const void *)argv);
-			if (errno != EACCES)
-				weprintf("execv %s:", dirpath);
-			_exit(1);
+		run_hook(dirpath, argv);
 
-		default:
-			/* SIGCHLD is ignored */
-			break;
-		}
-#endif
+		dirpath[dirpathlen] = '\0';
 	}
 
 	if (errno)
diff --git a/src/redshift.c b/src/redshift.c
index bcd9db9..5bc172e 100644
--- a/src/redshift.c
+++ b/src/redshift.c
@@ -538,5 +538,6 @@ out:
 		provider->free(provider_state);
 	if (method_state)
 		method->free(method_state);
+	free(hook_file);
 	return 0;
 }