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/mktemp.c

@@ -16,8 +16,10 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
 #include "libc/calls/calls.h"
-#include "libc/stdio/temp.h"
+#include "libc/sysv/consts/at.h"
+#include "libc/temp.h"
 
 /**
  * Generates temporary filename.
@@ -27,15 +29,20 @@
  *
  * @param template is mutated to replace last six X's with rng
  * @raise EINVAL if `template` didn't end with `XXXXXX`
- * @return pointer to mutated `template`, or 0 w/ errno
- * @see mkstemp()
+ * @return always `template` which on success will have its XXXXXX bytes
+ *     mutated to a random value, otherwise on error it'll hold an empty
+ *     string and `errno` will be set
+ * @see mkstemp() if you you need a file descriptor
+ * @see mkstemps() if you you need a file extension
+ * @see openatemp() for one temp roller to rule them all
+ * @see mkostemp() if you you need a `O_CLOEXEC`, `O_APPEND`, etc.
  */
 char *mktemp(char *template) {
   int fd;
-  if ((fd = mkstemp(template)) != -1) {
-    close(fd);
-    return template;
+  if ((fd = openatemp(AT_FDCWD, template, 0, 0, 0)) != -1) {
+    unassert(!close(fd));
   } else {
-    return 0;
+    *template = 0;
   }
+  return template;
 }