Make everything configurable

1 files changed, 178 insertions, 0 deletions

diff --git a/config.c b/config.c
new file mode 100644
index 0000000..bc1ec4f
--- /dev/null
+++ b/config.c
@@ -0,0 +1,178 @@
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <glob.h>
+#include <unistd.h>
+
+#define _IS_CONFIG_C
+#include "config.h"
+#undef _IS_CONFIG_C
+
+const char *wlan_interface;
+const char *eth_interface;
+const char *wmii_path;
+const char *time_format;
+const char *battery_path;
+bool use_colors;
+const char *wmii_normcolors;
+char order[MAX_ORDER][2];
+const char **run_watches;
+unsigned int num_run_watches;
+
+void die(const char *fmt, ...);
+
+/*
+ * This function exists primarily for resolving ~ in pathnames. However, you
+ * can also specify ~/Movies/ *, which will only return the first match!
+ *
+ */
+char *glob_path(const char *path) {
+	static glob_t globbuf;
+	if (glob(path, GLOB_NOCHECK | GLOB_TILDE, NULL, &globbuf) < 0)
+		die("glob() failed");
+	char *result = strdup(globbuf.gl_pathc > 0 ? globbuf.gl_pathv[0] : path);
+	globfree(&globbuf);
+	return result;
+}
+
+/*
+ * Loads configuration from configfile
+ *
+ */
+static void get_next_config_entry(FILE *handle, char **dest_name, char **dest_value, char *whole_buffer, int whole_buffer_size) {
+	char *ret;
+	if ((ret = fgets(whole_buffer, whole_buffer_size, handle)) == whole_buffer) {
+		char *c = whole_buffer;
+		/* Skip whitespaces in the beginning */
+		while (isspace((int)*c) && *c != '\0')
+			c++;
+		*dest_name = c;
+		while (!isspace((int)*c))
+			c++;
+		/* Terminate string as soon as whitespaces begin or it's terminated anyway */
+		*(c++) = '\0';
+
+		/* Same for the value: strip whitespaces */
+		while (isspace((int)*c) && *c != '\0')
+			c++;
+		*dest_value = c;
+		/* Whitespace is allowed, newline/carriage return is not */
+		while ((*c != '\n') && (*c != '\r') && (*c != '\0'))
+			c++;
+		*c = 0;
+	} else if (ret != NULL)
+		die("Could not read line in configuration file");
+}
+
+/*
+ * Reads the configuration from the given file
+ *
+ */
+int load_configuration(const char *configfile) {
+	#define OPT(x) else if (strcasecmp(dest_name, x) == 0)
+
+	/* Check if the file exists */
+	struct stat buf;
+	if (stat(configfile, &buf) < 0)
+		return -1;
+
+	int result = 0;
+	FILE *handle = fopen(configfile, "r");
+	if (handle == NULL)
+		die("Could not open configfile");
+	char *dest_name = NULL, *dest_value = NULL, whole_buffer[1026];
+	struct stat stbuf;
+	while (!feof(handle)) {
+		get_next_config_entry(handle, &dest_name, &dest_value, whole_buffer, 1024);
+		/* No more entries? We're done! */
+		if (dest_name == NULL)
+			break;
+		/* Skip comments and empty lines */
+		if (dest_name[0] == '#' || strlen(dest_name) < 3)
+			continue;
+
+		OPT("wlan")
+		{
+			wlan_interface = strdup(dest_value);
+		}
+		OPT("eth")
+		{
+			eth_interface = strdup(dest_value);
+		}
+		OPT("wmii_path")
+		{
+			char *globbed = glob_path(dest_value);
+			if ((stat(globbed, &stbuf)) == -1)
+				die("wmii_path contains an invalid path");
+			if (globbed[strlen(globbed)-1] != '/')
+				die("wmii_path is not terminated by /");
+			wmii_path = globbed;
+		}
+		OPT("time_format")
+		{
+			time_format = strdup(dest_value);
+		}
+		OPT("battery_path")
+		{
+			if ((stat(dest_value, &stbuf)) == -1)
+				die("battery_path contains an invalid path");
+			battery_path = strdup(dest_value);
+		}
+		OPT("run_watch")
+		{
+			char *name = strdup(dest_value);
+			char *path = name;
+			while (*path != ' ')
+				path++;
+			*(path++) = '\0';
+			num_run_watches += 2;
+			run_watches = realloc(run_watches, sizeof(char*) * num_run_watches);
+			run_watches[num_run_watches-2] = name;
+			run_watches[num_run_watches-1] = path;
+		}
+		OPT("order")
+		{
+			#define SET_ORDER(opt, idx) { if (strcasecmp(token, opt) == 0) sprintf(order[idx], "%d", c++); }
+			char *walk, *token;
+			int c = 0;
+			walk = token = dest_value;
+			while (*walk != '\0') {
+				while ((*walk != ',') && (*walk != '\0'))
+					walk++;
+				*(walk++) = '\0';
+				SET_ORDER("run", ORDER_RUN);
+				SET_ORDER("wlan", ORDER_WLAN);
+				SET_ORDER("eth", ORDER_ETH);
+				SET_ORDER("battery", ORDER_BATTERY);
+				SET_ORDER("load", ORDER_LOAD);
+				SET_ORDER("time", ORDER_TIME);
+				token = walk;
+			}
+		}
+		OPT("color")
+		{
+			use_colors = true;
+		}
+		OPT("normcolors")
+		{
+			wmii_normcolors = strdup(dest_value);
+		}
+		else
+		{
+			result = -2;
+			die("Unknown configfile option: %s\n", dest_name);
+		}
+		dest_name = dest_value = NULL;
+	}
+	fclose(handle);
+
+	if (wmii_path == NULL)
+		die("No wmii_path specified in configuration file");
+
+	return result;
+}