mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
a4b455185b
Renaming gc() to _gc() was a mistake since the better thing to do is put it behind the _COSMO_SOURCE macro. We need this change because I haven't wanted to use my amazing garbage collector ever since we renamed it. You now need to define _COSMO_SOURCE yourself when using amalgamation header and cosmocc users need to pass the -mcosmo flag to get the gc() function Some other issues relating to cancelation have been fixed along the way. We're also now putting cosmocc in a folder named `.cosmocc` so it can be more safely excluded by grep --exclude-dir=.cosmocc --exclude-dir=o etc.
75 lines
3.5 KiB
C
75 lines
3.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│ vi: set et 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/calls/calls.h"
|
|
#include "libc/stdio/stdio.h"
|
|
#include "libc/temp.h"
|
|
|
|
/**
|
|
* Opens stream backed by anonymous file, e.g.
|
|
*
|
|
* FILE *f;
|
|
* if (!(f = tmpfile())) {
|
|
* perror("tmpfile");
|
|
* exit(1);
|
|
* }
|
|
* // do stuff
|
|
* fclose(f);
|
|
*
|
|
* This creates a secure temporary file inside $TMPDIR. If it isn't
|
|
* defined, then /tmp is used on UNIX and GetTempPath() is used on the
|
|
* New Technology. This resolution of $TMPDIR happens once in a ctor.
|
|
*
|
|
* Once fclose() is called, the returned file is guaranteed to be
|
|
* deleted automatically. On UNIX the file is unlink()'d before this
|
|
* function returns. On the New Technology it happens upon fclose().
|
|
*
|
|
* On newer Linux only (c. 2013) it's possible to turn the anonymous
|
|
* returned file back into a real file, by doing this:
|
|
*
|
|
* linkat(AT_FDCWD, gc(xasprintf("/proc/self/fd/%d", fileno(f))),
|
|
* AT_FDCWD, "real.txt", AT_SYMLINK_FOLLOW)
|
|
*
|
|
* On the New Technology, temporary files created by this function
|
|
* should have better performance, because `kNtFileAttributeTemporary`
|
|
* asks the kernel to more aggressively cache and reduce i/o ops.
|
|
*
|
|
* Favor tmpfd() or tmpfile() over `open(O_TMPFILE)` because the latter
|
|
* is Linux-only and will cause open() failures on all other platforms.
|
|
*
|
|
* @see tmpfd() if you don't want to link stdio/malloc
|
|
* @raise ECANCELED if thread was cancelled in masked mode
|
|
* @raise EINTR if signal was delivered
|
|
* @cancelationpoint
|
|
* @asyncsignalsafe
|
|
* @vforksafe
|
|
*/
|
|
FILE *tmpfile(void) {
|
|
int fd;
|
|
FILE *f;
|
|
if ((fd = tmpfd()) != -1) {
|
|
if ((f = fdopen(fd, "w+"))) {
|
|
return f;
|
|
} else {
|
|
close(fd);
|
|
return 0;
|
|
}
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|