Annotation of mandoc/compat_mkstemps.c, Revision 1.1
1.1 ! schwarze 1: /* $Id$ */
! 2: /*
! 3: * Copyright (c) 2015, 2021 Ingo Schwarze <schwarze@openbsd.org>
! 4: *
! 5: * Permission to use, copy, modify, and distribute this software for any
! 6: * purpose with or without fee is hereby granted, provided that the above
! 7: * copyright notice and this permission notice appear in all copies.
! 8: *
! 9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
! 10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
! 11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
! 12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
! 13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
! 14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
! 15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
! 16: *
! 17: * Parts of the algorithm of this function are inspired by OpenBSD
! 18: * mkdtemp(3) by Theo de Raadt and Todd Miller, but the code differs.
! 19: */
! 20: #include "config.h"
! 21:
! 22: #include <sys/stat.h>
! 23: #include <errno.h>
! 24: #include <fcntl.h>
! 25: #include <limits.h>
! 26: #include <stdlib.h>
! 27: #include <string.h>
! 28:
! 29: int
! 30: mkstemps(char *path, int suffixlen)
! 31: {
! 32: char *start, *end, *cp;
! 33: int fd, tries;
! 34: char backup;
! 35:
! 36: end = strchr(path, '\0');
! 37: if (suffixlen < 0 || suffixlen > end - path - 6) {
! 38: errno = EINVAL;
! 39: return -1;
! 40: }
! 41: end -= suffixlen;
! 42: for (start = end; start > path; start--)
! 43: if (start[-1] != 'X')
! 44: break;
! 45:
! 46: backup = *end;
! 47: for (tries = INT_MAX; tries; tries--) {
! 48: *end = '\0';
! 49: cp = mktemp(path);
! 50: *end = backup;
! 51: if (cp == NULL)
! 52: return -1;
! 53: fd = open(path, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
! 54: if (fd != -1)
! 55: return fd;
! 56: for (cp = start; cp < end; cp++)
! 57: *cp = 'X';
! 58: if (errno != EEXIST)
! 59: return -1;
! 60: }
! 61: errno = EEXIST;
! 62: return -1;
! 63: }
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