cosmopolitan/third_party/musl/tempnam.c

85 lines
4.0 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│
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ Musl Libc │
│ Copyright © 2005-2014 Rich Felker, et al. │
│ │
│ Permission is hereby granted, free of charge, to any person obtaining │
│ a copy of this software and associated documentation files (the │
│ "Software"), to deal in the Software without restriction, including │
│ without limitation the rights to use, copy, modify, merge, publish, │
│ distribute, sublicense, and/or sell copies of the Software, and to │
│ permit persons to whom the Software is furnished to do so, subject to │
│ the following conditions: │
│ │
│ The above copyright notice and this permission notice shall be │
│ included in all copies or substantial portions of the Software. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/stat.h"
#include "libc/calls/struct/timespec.h"
#include "libc/errno.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/at.h"
#include "libc/sysv/consts/clock.h"
#include "libc/time/time.h"
#include "third_party/musl/tempnam.h"
#define MAXTRIES 100
asm(".ident\t\"\\n\\n\
Musl libc (MIT License)\\n\
Copyright 2005-2014 Rich Felker, et. al.\"");
asm(".include \"libc/disclaimer.inc\"");
static char *__randname(char *template) {
int i;
struct timespec ts;
unsigned long r;
clock_gettime(CLOCK_REALTIME, &ts);
r = ts.tv_nsec * 65537 ^ (uintptr_t)&ts / 16 + (uintptr_t) template;
for (i = 0; i < 6; i++, r >>= 5) template[i] = 'A' + (r & 15) + (r & 16) * 2;
return template;
}
/**
* Creates name for temporary file.
*/
char *tempnam(const char *dir, const char *pfx) {
int i, r;
char s[PATH_MAX];
size_t l, dl, pl;
if (!dir) dir = kTmpPath;
if (!pfx) pfx = "temp";
dl = strlen(dir);
pl = strlen(pfx);
l = dl + 1 + pl + 1 + 6;
if (l >= PATH_MAX) {
errno = ENAMETOOLONG;
return 0;
}
memcpy(s, dir, dl);
s[dl] = '/';
memcpy(s + dl + 1, pfx, pl);
s[dl + 1 + pl] = '_';
s[l] = 0;
for (i = 0; i < MAXTRIES; i++) {
__randname(s + l - 6);
r = fstatat(AT_FDCWD, s, &(struct stat){0}, AT_SYMLINK_NOFOLLOW);
if (r == -ENOENT) return strdup(s);
}
return 0;
}