| /* Copyright (C) 1991-2017 Free Software Foundation, Inc. |
| This file is derived from mkstemp.c from the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with the GNU C Library; see the file COPYING.LIB. If not, |
| write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include <sys/types.h> |
| #ifdef HAVE_STDLIB_H |
| #include <stdlib.h> |
| #endif |
| #ifdef HAVE_STRING_H |
| #include <string.h> |
| #endif |
| #include <errno.h> |
| #include <stdio.h> |
| #include <fcntl.h> |
| #ifdef HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #ifdef HAVE_SYS_TIME_H |
| #include <sys/time.h> |
| #elif HAVE_TIME_H |
| #include <time.h> |
| #endif |
| #include "ansidecl.h" |
| |
| /* We need to provide a type for gcc_uint64_t. */ |
| #ifdef __GNUC__ |
| __extension__ typedef unsigned long long gcc_uint64_t; |
| #else |
| typedef unsigned long gcc_uint64_t; |
| #endif |
| |
| #ifndef TMP_MAX |
| #define TMP_MAX 16384 |
| #endif |
| |
| #ifndef O_BINARY |
| # define O_BINARY 0 |
| #endif |
| |
| /* |
| |
| @deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len}) |
| |
| Generate a unique temporary file name from @var{pattern}. |
| @var{pattern} has the form: |
| |
| @example |
| @var{path}/ccXXXXXX@var{suffix} |
| @end example |
| |
| @var{suffix_len} tells us how long @var{suffix} is (it can be zero |
| length). The last six characters of @var{pattern} before @var{suffix} |
| must be @samp{XXXXXX}; they are replaced with a string that makes the |
| filename unique. Returns a file descriptor open on the file for |
| reading and writing. |
| |
| @end deftypefn |
| |
| */ |
| |
| int |
| mkstemps (char *pattern, int suffix_len) |
| { |
| static const char letters[] |
| = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; |
| static gcc_uint64_t value; |
| #ifdef HAVE_GETTIMEOFDAY |
| struct timeval tv; |
| #endif |
| char *XXXXXX; |
| size_t len; |
| int count; |
| |
| len = strlen (pattern); |
| |
| if ((int) len < 6 + suffix_len |
| || strncmp (&pattern[len - 6 - suffix_len], "XXXXXX", 6)) |
| { |
| return -1; |
| } |
| |
| XXXXXX = &pattern[len - 6 - suffix_len]; |
| |
| #ifdef HAVE_GETTIMEOFDAY |
| /* Get some more or less random data. */ |
| gettimeofday (&tv, NULL); |
| value += ((gcc_uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid (); |
| #else |
| value += getpid (); |
| #endif |
| |
| for (count = 0; count < TMP_MAX; ++count) |
| { |
| gcc_uint64_t v = value; |
| int fd; |
| |
| /* Fill in the random bits. */ |
| XXXXXX[0] = letters[v % 62]; |
| v /= 62; |
| XXXXXX[1] = letters[v % 62]; |
| v /= 62; |
| XXXXXX[2] = letters[v % 62]; |
| v /= 62; |
| XXXXXX[3] = letters[v % 62]; |
| v /= 62; |
| XXXXXX[4] = letters[v % 62]; |
| v /= 62; |
| XXXXXX[5] = letters[v % 62]; |
| |
| fd = open (pattern, O_BINARY|O_RDWR|O_CREAT|O_EXCL, 0600); |
| if (fd >= 0) |
| /* The file does not exist. */ |
| return fd; |
| if (errno != EEXIST |
| #ifdef EISDIR |
| && errno != EISDIR |
| #endif |
| ) |
| /* Fatal error (EPERM, ENOSPC etc). Doesn't make sense to loop. */ |
| break; |
| |
| /* This is a random value. It is only necessary that the next |
| TMP_MAX values generated by adding 7777 to VALUE are different |
| with (module 2^32). */ |
| value += 7777; |
| } |
| |
| /* We return the null string if we can't find a unique file name. */ |
| pattern[0] = '\0'; |
| return -1; |
| } |