Removed submodules

p1-sh/utils/chmod.c

@@ -0,0 +1,70 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+static void usage (void);
+
+mode_t
+calculate_permission (char *arg_str)
+{
+  const char perms[4] = "rwx";
+
+  if (strlen (arg_str) != 3)
+    {
+      usage ();
+      exit (EXIT_FAILURE);
+    }
+
+  mode_t permission = 0;
+
+  for (size_t j = 0; j < 3; j++)
+    {
+      int perm = 1 << (2 - j);
+      if (arg_str[j] == perms[j])
+        {
+          permission |= perm;
+        }
+      else if (arg_str[j] != '-')
+        {
+          usage ();
+          exit (EXIT_FAILURE);
+        }
+    }
+
+  return permission;
+}
+
+int
+main (int argc, char **argv)
+{
+  if (argc != 5)
+    {
+      usage ();
+      return EXIT_FAILURE;
+    }
+
+  mode_t user = calculate_permission (argv[1]);
+  mode_t group = calculate_permission (argv[2]);
+  mode_t other = calculate_permission (argv[3]);
+
+  mode_t permissions = (user << 6) | (group << 3) | other;
+
+  if (chmod (argv[4], permissions) == -1)
+    {
+      perror ("Failed to chmod");
+      return EXIT_FAILURE;
+    }
+
+  return EXIT_SUCCESS;
+}
+
+static void
+usage (void)
+{
+  printf ("chmod, changes permissions on a file\n");
+  printf ("usage: chmod USR GRP OTH FILE\n\n");
+  printf ("USR, GRP, and OTH must be of the rwx format,\n");
+  printf ("with - indicating a permission is not allwed.\n");
+}