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/*-*- 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/assert.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/dce.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/isslash.internal.h"
#include "libc/fmt/itoa.h"
#include "libc/nt/createfile.h"
#include "libc/nt/enum/accessmask.h"
#include "libc/nt/enum/creationdisposition.h"
#include "libc/nt/enum/fileflagandattributes.h"
#include "libc/nt/enum/filesharemode.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/at.h"
#include "libc/sysv/consts/o.h"
static struct OpenAnon { int count; } g_openanon;
static void openanon$genpath(const char *name, struct OpenAnon *state,
char pathbuf[hasatleast PATH_MAX]) {
char c;
size_t i;
char *p, *pe;
p = stpcpy(pathbuf, kTmpPath);
pe = pathbuf + PATH_MAX - 8 - 10 - 1 - 10 - 1;
if (!name) name = "openanon";
for (i = 0; p < pe; ++i) {
if (!(c = name[i])) break;
if (isslash(c)) c = '_';
*p++ = c;
}
*p++ = '.';
p += uint64toarray_radix10(getpid(), p);
*p++ = '.';
p += uint64toarray_radix10(++state->count, p);
*p = '\0';
assert(p < pe);
}
static int openanon$impl(const char *name, unsigned flags,
struct OpenAnon *state,
char pathbuf[hasatleast PATH_MAX]) {
int fd;
openanon$genpath(name, state, pathbuf);
flags |= O_RDWR | O_CREAT | O_EXCL | O_TRUNC;
if (!IsWindows()) {
if ((fd = openat$sysv(AT_FDCWD, pathbuf, flags, 0600)) != -1) {
unlink(pathbuf);
}
return fd;
} else {
if ((fd = __getemptyfd()) != -1 &&
(g_fds.p[fd].handle = CreateFileA(
pathbuf, kNtGenericRead | kNtGenericWrite, kNtFileShareExclusive,
&kNtIsInheritable, kNtCreateAlways,
(kNtFileAttributeNotContentIndexed | kNtFileAttributeNormal |
kNtFileAttributeTemporary | kNtFileFlagDeleteOnClose),
0)) != -1) {
g_fds.p[fd].kind = kFdFile;
g_fds.p[fd].flags = flags;
return fd;
} else {
return __winerr();
}
}
}
/**
* Creates anonymous file.
*
* @param name is purely informative
* @param flags can have O_CLOEXEC
* @return fd of file with no name, needing close(), or -1 w/ errno
* @see memfd_create() if disk-paranoid
* @see mkostempsm() for named files
*/
int openanon(char *name, unsigned flags) {
char pathbuf[PATH_MAX];
return openanon$impl(name, flags, &g_openanon, pathbuf);
}