From 7095bedd256b07e80f6f852622025a899f7af1da Mon Sep 17 00:00:00 2001
From: Kenny Levinsen <kl@kl.wtf>
Date: Fri, 25 Sep 2020 11:41:33 +0200
Subject: [PATCH] Accept user-specified config path

Adds a -c,--config command line option that allows the user to specify
an arbitrary config path.
---
 kanshi.1.scd | 10 +++++++++-
 main.c       | 39 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/kanshi.1.scd b/kanshi.1.scd
index 8577a4b..f50c7f6 100644
--- a/kanshi.1.scd
+++ b/kanshi.1.scd
@@ -6,7 +6,15 @@ kanshi - dynamic output configuration
 
 # DESCRIPTION
 
-*kanshi*
+*kanshi* [options...]
+
+# OPTIONS
+
+*-h, --help*
+	Show help message and quit.
+
+*-c, --config* <config>
+	Specifies a config file.
 
 # SYNOPSIS
 
diff --git a/main.c b/main.c
index 67ea446..b7f974c 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,7 @@
 #define _POSIX_C_SOURCE 200809L
 #include <assert.h>
 #include <errno.h>
+#include <getopt.h>
 #include <limits.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -453,7 +454,11 @@ static const struct wl_registry_listener registry_listener = {
 	.global_remove = registry_handle_global_remove,
 };
 
-static struct kanshi_config *read_config(void) {
+static struct kanshi_config *read_config(const char *config) {
+	if (config != NULL) {
+		return parse_config(config);
+	}
+
 	const char config_filename[] = "kanshi/config";
 	char config_path[PATH_MAX];
 	const char *xdg_config_home = getenv("XDG_CONFIG_HOME");
@@ -472,12 +477,42 @@ static struct kanshi_config *read_config(void) {
 	return parse_config(config_path);
 }
 
+static const char usage[] = "Usage: %s [options...]\n"
+"  -h, --help           Show help message and quit\n"
+"  -c, --config <path>  Path to config file.\n";
+
+static const struct option long_options[] = {
+	{"help", no_argument, 0, 'h'},
+	{"config", required_argument, 0, 'c'},
+	{0},
+};
+
 int main(int argc, char *argv[]) {
-	struct kanshi_config *config = read_config();
+	char *config_arg = NULL;
+
+	int opt;
+	while ((opt = getopt_long(argc, argv, "hc:", long_options, NULL)) != -1) {
+		switch (opt) {
+		case 'c':
+			free(config_arg);
+			config_arg = strdup(optarg);
+			break;
+		case 'h':
+			fprintf(stderr, usage, argv[0]);
+			return EXIT_SUCCESS;
+		default:
+			fprintf(stderr, usage, argv[0]);
+			return EXIT_FAILURE;
+		}
+	}
+
+	struct kanshi_config *config = read_config(config_arg);
 	if (config == NULL) {
 		return EXIT_FAILURE;
 	}
 
+	free(config_arg);
+
 	struct wl_display *display = wl_display_connect(NULL);
 	if (display == NULL) {
 		fprintf(stderr, "failed to connect to display\n");