add kcmdline

apps/kcmdline.c

@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <toaru/hashmap.h>
+
+hashmap_t * args_map = NULL;
+
+int tokenize(char * str, char * sep, char **buf) {
+	char * pch_i;
+	char * save_i;
+	int    argc = 0;
+	pch_i = strtok_r(str,sep,&save_i);
+	if (!pch_i) { return 0; }
+	while (pch_i != NULL) {
+		buf[argc] = (char *)pch_i;
+		++argc;
+		pch_i = strtok_r(NULL,sep,&save_i);
+	}
+	buf[argc] = NULL;
+	return argc;
+}
+
+void args_parse(char * _arg) {
+	char * arg = strdup(_arg);
+	char * argv[1024];
+	int argc = tokenize(arg, " ", argv);
+
+	for (int i = 0; i < argc; ++i) {
+		char * c = strdup(argv[i]);
+
+		char * name;
+		char * value;
+
+		name = c;
+		value = NULL;
+		/* Find the first = and replace it with a null */
+		char * v = c;
+		while (*v) {
+			if (*v == '=') {
+				*v = '\0';
+				v++;
+				value = v;
+				goto _break;
+			}
+			v++;
+		}
+
+_break:
+		hashmap_set(args_map, name, value);
+	}
+
+	free(arg);
+}
+
+void show_usage(int argc, char * argv[]) {
+	printf(
+			"kcmdline - query the kernel command line\n"
+			"\n"
+			"usage: %s -g ARG...\n"
+			"       %s -q ARG...\n"
+			"\n"
+			" -g     \033[3mprint the value for the requested argument\033[0m\n"
+			" -q     \033[3mquery whether the requested argument is present (0 = yes)\033[0m\n"
+			" -?     \033[3mshow this help text\033[0m\n"
+			"\n", argv[0], argv[0]);
+}
+
+int main(int argc, char * argv[]) {
+	/* Open */
+	FILE * f = fopen("/proc/cmdline", "r");
+	if (!f) return 1;
+
+	/* Read */
+	char * cmdline = malloc(4096); /* cmdline can't be longer than that */
+	memset(cmdline, 0, 4096);
+	size_t size = fread(cmdline, 1, 4096, f);
+	fclose(f);
+
+	/* Parse */
+	args_map = hashmap_create(10);
+	args_parse(cmdline);
+	free(cmdline);
+
+	/* Figure out what we're doing */
+	int opt;
+	while ((opt = getopt(argc, argv, "?g:q:s")) != -1) {
+		switch (opt) {
+			case 'g':
+				if (hashmap_has(args_map, optarg)) {
+					printf("%s\n", hashmap_get(args_map, optarg));
+					return 0;
+				} else {
+					return 1;
+				}
+			case 'q':
+				return !hashmap_has(args_map,optarg);
+			case 's':
+				return size;
+			case '?':
+				show_usage(argc, argv);
+				return 0;
+		}
+	}
+}