1 files changed, 26 insertions, 5 deletions

diff --git a/src/commands/groups.c b/command/groups.c
index bd2e5f9..cb950be 100644
--- a/src/commands/groups.c
+++ b/command/groups.c
@@ -1,20 +1,41 @@
-#include "../command.h"
+#include "args.h"
+#include "command.h"
+#include "lslib.h"
 
+#include <errno.h>
 #include <grp.h>
 #include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
-COMMAND_EMPTY(groups) {
+static void help (void) {
+    printf("Usage: groups [USER]\n\n");
+    printf("Print the groups USER is in\n");
+}
+
+COMMAND(groups) {
 
     uid_t uid;
     int ngroups, i;
     gid_t* groups;
     struct passwd* pw;
 
-    uid = getuid();
+    parse_help(argc, argv, help);
     
-    pw = getpwuid(uid);
+    if (argc < 1) {
+        uid = getuid();
+        pw = getpwuid(uid);
+    } else {
+        pw = getpwnam(argv[0]);
+    }
+
     if(pw == NULL){
-        error("failed to fetch groups: %s", strerror(errno));
+        if (errno == 0) {
+            error("user not found");
+        } else {
+            error("failed to fetch groups: %s", strerror(errno));
+        }
     }
     
     ngroups = 0;