Make improvements

- Invent openatemp() API
- Invent O_UNLINK open flag
- Introduce getenv_secure() API
- Remove `git pull` from cosmocc
- Fix utimes() when path is NULL
- Fix mktemp() to never return NULL
- Fix utimensat() UTIME_OMIT on XNU
- Improve utimensat() code for RHEL5
- Turn `argv[0]` C:/ to /C/ on Windows
- Introduce tmpnam() and tmpnam_r() APIs
- Fix more const issues with internal APIs
- Permit utimes() on WIN32 in O_RDONLY mode
- Fix fdopendir() to check fd is a directory
- Fix recent crash regression in landlock make
- Fix futimens(AT_FDCWD, NULL) to return EBADF
- Use workaround so `make -j` doesn't fork bomb
- Rename dontdiscard to __wur (just like glibc)
- Fix st_size for WIN32 symlinks containing UTF-8
- Introduce stdio ext APIs needed by GNU coreutils
- Fix lstat() on WIN32 for symlinks to directories
- Move some constants from normalize.inc to limits.h
- Fix segv with memchr() and memcmp() overlapping page
- Implement POSIX fflush() behavior for reader streams
- Implement AT_SYMLINK_NOFOLLOW for utimensat() on WIN32
- Don't change read-only status of existing files on WIN32
- Correctly handle `0x[^[:xdigit:]]` case in strtol() functions

libc/calls/mkstemps.c

@@ -0,0 +1,44 @@
+/*-*- 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 2020 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/temp.h"
+#include "libc/sysv/consts/at.h"
+
+/**
+ * Creates temporary file name and file descriptor, e.g.
+ *
+ *     char path[] = "/tmp/foo.XXXXXX.txt";
+ *     int fd = mkstemps(path, 4);
+ *     printf("%s is opened as %d\n", path, fd);
+ *
+ * @param template is mutated to replace last six X's with rng
+ * @param suffixlen may be nonzero to permit characters after the "XXXXXX"
+ * @return open file descriptor r + w exclusive or -1 w/ errno
+ * @raise EINVAL if `template` (less the `suffixlen` region) didn't
+ *     end with the string "XXXXXXX"
+ * @see mkostemp() if you you need a `O_CLOEXEC`, `O_APPEND`, etc.
+ * @see openatemp() for one temp roller to rule them all
+ * @see mkstemp() if you don't need `suffixlen`
+ * @see mktemp() if you don't need an fd
+ * @see tmpfd() if you don't need a path
+ */
+int mkstemps(char *template, int suffixlen) {
+  return openatemp(AT_FDCWD, template, suffixlen, 0, 0);
+}
+
+__strong_reference(mkstemps, mkstemps64);