plan9 chmod

mychmod.c

#include <u.h>
#include <libc.h>

const int STDERR = 2;

static void 
usage (void)
{
  fprint (STDERR, "usage: %s 0644 file1 [file2] ...\n", argv0);
  exits ("usage");
}

void
mychmod (const ulong nmode, const char* fname)
{
  Dir d;
  nulldir (&d);
  d.mode = nmode;

  if (-1 == dirwstat (fname, &d))
  {
      sysfatal ("dirwstat: %r");
  }
}

void 
main (int argc, char* argv[])
{
  ARGBEGIN
  {
    default:
      usage ();
  }
  ARGEND;

  if (argc < 2)
  {
      usage ();
  }

  const int MASK_BASE = 8;
  ulong perm_mask = strtoul (argv[0], nil, MASK_BASE);
  if (0 == perm_mask)
  {
      sysfatal ("invalid mode: '%s'", argv[0]);
  }
	
  for (int i = 1; i != argc; ++i)
  {
      mychmod (perm_mask, argv[i]);
  }

  exits (nil);
}