cosmopolitan/libc/calls/umask.c
Justine Tunney 965516e313
Make improvements for Actually Portable Emacs
- Get SIGWINCH working again on the New Technology
- Correctly handle O_NOFOLLOW in open() on Windows
- Implement synthetic umask() functionality on Windows
- Do a better job managing file execute access on Windows
- Fill in `st_uid` and `st_gid` with username hash on Windows
- Munge UNICODE control pictures into control codes on Windows
- Do a better job ensuring Windows console settings are restored
- Introduce KPRINTF_LOG environment variable to log kprintf to a file
2023-08-19 06:44:58 -07:00

48 lines
2.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/strace.internal.h"
#include "libc/sysv/consts/nr.h"
/**
* Sets file mode creation mask.
*
* On Windows, the value of umask() determines how Cosmopolitan goes
* about creating synthetic `st_mode` bits. The default umask is 077
* which is based on the assumption that Windows is being used for a
* single user. Don't assume that Cosmopolitan Libc will help you to
* secure a multitenant Windows computer.
*
* @return previous mask
* @note always succeeds
*/
unsigned umask(unsigned newmask) {
int oldmask;
if (!IsWindows()) {
oldmask = sys_umask(newmask);
} else {
oldmask = atomic_exchange(&__umask, newmask);
}
STRACE("umask(%#o) → %#o", oldmask);
return oldmask;
}