add help
diff --git a/ebtablesu.c b/ebtablesu.c
index 9aab70b..cd86783 100644
--- a/ebtablesu.c
+++ b/ebtablesu.c
@@ -7,18 +7,26 @@
#include <fcntl.h>
#include <errno.h>
+static void print_help()
+{
+ printf("ebtablesu v"PROGVERSION" ("PROGDATE")\n");
+ printf(
+"Usage:\n"
+"ebtablesu open table : copy the kernel table\n"
+"ebtablesu fopen table file : copy the table from the specified file\n"
+"ebtablesu free table : remove the table from memory\n"
+"ebtablesu commit table : commit the table to the kernel\n"
+"ebtablesu fcommit table file : commit the table to the specified file\n\n"
+"ebtablesu <ebtables options> : the ebtables specifications\n"
+" use spaces only to separate options and commands\n"
+"For the ebtables options, see\n# ebtables -h\nor\n# man ebtables\n"
+ );
+}
int main(int argc, char *argv[])
{
char *arguments, *pos;
int i, writefd, len = 0;
- if ((writefd = open(EBTD_PIPE, O_WRONLY, 0)) == -1) {
- fprintf(stderr, "Could not open the pipe, perhaps ebtablesd is "
- "not running or you don't have write permission (try "
- "running as root).\n");
- return -1;
- }
-
if (argc > EBTD_ARGC_MAX) {
fprintf(stderr, "ebtablesd accepts at most %d arguments, %d "
"arguments were specified. If you need this many "
@@ -43,11 +51,27 @@
return -1;
}
+ if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
+ if (argc != 2) {
+ fprintf(stderr, "%s does not accept options.\n", argv[1]);
+ return -1;
+ }
+ print_help();
+ exit(0);
+ }
+
if (!(arguments = (char *)malloc(len))) {
fprintf(stderr, "ebtablesu: out of memory.\n");
return -1;
}
+ if ((writefd = open(EBTD_PIPE, O_WRONLY, 0)) == -1) {
+ fprintf(stderr, "Could not open the pipe, perhaps ebtablesd is "
+ "not running or you don't have write permission (try "
+ "running as root).\n");
+ return -1;
+ }
+
pos = arguments;
for (i = 0; i < argc; i++) {
strcpy(pos, argv[i]);