Add argument parsing + switch for uncached operation

This adds support for the following options to cgit:
  --root=<path>
  --cache=<path>
  --nocache
  --query=<querystring>
  --repo=<reponame>
  --page=<pagename>
  --head=<branchname>
  --sha1=<sha1>
  --ofs=<number>

On startup, /etc/cgitrc is parsed, followed by argument parsing and
finally querystring parsing.

If --nocache is specified (or set in /etc/gitrc), caching is disabled and
cgit instead generates pages to stdout.

The combined effect of these two changes makes testing/debugging a lot
less painfull.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

cgit.c

@@ -96,15 +96,59 @@ static void cgit_print_cache(struct cacheitem *item)
 	close(fd);
 }
 
+static void cgit_parse_args(int argc, const char **argv)
+{
+	int i;
+
+	for (i = 1; i < argc; i++) {
+		if (!strncmp(argv[i], "--root=", 7)) {
+			cgit_root = xstrdup(argv[i]+7);
+		}
+		if (!strncmp(argv[i], "--cache=", 8)) {
+			cgit_cache_root = xstrdup(argv[i]+8);
+		}
+		if (!strcmp(argv[i], "--nocache")) {
+			cgit_nocache = 1;
+		}
+		if (!strncmp(argv[i], "--query=", 8)) {
+			cgit_querystring = xstrdup(argv[i]+8);
+		}
+		if (!strncmp(argv[i], "--repo=", 7)) {
+			cgit_query_repo = xstrdup(argv[i]+7);
+		}
+		if (!strncmp(argv[i], "--page=", 7)) {
+			cgit_query_page = xstrdup(argv[i]+7);
+		}
+		if (!strncmp(argv[i], "--head=", 7)) {
+			cgit_query_head = xstrdup(argv[i]+7);
+			cgit_query_has_symref = 1;
+		}
+		if (!strncmp(argv[i], "--sha1=", 7)) {
+			cgit_query_sha1 = xstrdup(argv[i]+7);
+			cgit_query_has_sha1 = 1;
+		}
+		if (!strncmp(argv[i], "--ofs=", 6)) {
+			cgit_query_ofs = atoi(argv[i]+6);
+		}
+	}
+}
+
 int main(int argc, const char **argv)
 {
 	struct cacheitem item;
 
 	cgit_read_config("/etc/cgitrc", cgit_global_config_cb);
-	cgit_querystring = xstrdup(getenv("QUERY_STRING"));
+	if (getenv("QUERY_STRING"))
+		cgit_querystring = xstrdup(getenv("QUERY_STRING"));
+	cgit_parse_args(argc, argv);
 	cgit_parse_query(cgit_querystring, cgit_querystring_cb);
 
-	cgit_check_cache(&item);
+	if (cgit_nocache) {
-	cgit_print_cache(&item);
+		item.fd = STDOUT_FILENO;
+		cgit_fill_cache(&item);
+	} else {
+		cgit_check_cache(&item);
+		cgit_print_cache(&item);
+	}
 	return 0;
 }

cgit.h

@@ -33,6 +33,7 @@ extern char *cgit_logo_link;
 extern char *cgit_virtual_root;
 extern char *cgit_cache_root;
 
+extern int cgit_nocache;
 extern int cgit_max_lock_attempts;
 extern int cgit_cache_root_ttl;
 extern int cgit_cache_repo_ttl;

shared.c

@@ -17,6 +17,7 @@ char *cgit_virtual_root = NULL;
 
 char *cgit_cache_root   = "/var/cache/cgit";
 
+int cgit_nocache               =  0;
 int cgit_max_lock_attempts     =  5;
 int cgit_cache_root_ttl        =  5;
 int cgit_cache_repo_ttl        =  5;
@@ -54,6 +55,8 @@ void cgit_global_config_cb(const char *name, const char *value)
 		cgit_logo_link = xstrdup(value);
 	else if (!strcmp(name, "virtual-root"))
 		cgit_virtual_root = xstrdup(value);
+	else if (!strcmp(name, "nocache"))
+		cgit_nocache = atoi(value);
 }
 
 void cgit_repo_config_cb(const char *name, const char *value)