Initial commit 2.0

chkgrp-min.c

@@ -0,0 +1,48 @@
+/**
+ * chkgrp-min is a program that checks if a user is a member of a group.
+ *
+ * Author: Johannes Findeisen <you@hanez.org> - 2025
+ * Homepage: https://git.xw3.org/hanez/chkgrp
+ * License: Apache-2.0 (see LICENSE)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pwd.h>
+#include <grp.h>
+
+#define MAX_NAME 256
+
+int main(int argc, char *argv[])
+{
+    if (argc != 3)
+        return 2;
+
+    if (strlen(argv[1]) > MAX_NAME || strlen(argv[2]) > MAX_NAME)
+        return 2;
+
+    struct passwd *pw = getpwnam(argv[1]);
+    if (!pw)
+        return 2;
+
+    struct group *gr = getgrnam(argv[2]);
+    if (!gr)
+        return 2;
+
+    if (pw->pw_gid == gr->gr_gid) {
+        puts("Yes");
+        return 0;
+    }
+
+    for (char **m = gr->gr_mem; *m; ++m) {
+        if (!strcmp(*m, argv[1])) {
+            puts("Yes");
+            return 0;
+        }
+    }
+
+    puts("No");
+    return 1;
+}
+