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author | Raja R Harinath <harinath@src.gnome.org> | 1998-07-01 01:22:38 +0000 |
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committer | Raja R Harinath <harinath@src.gnome.org> | 1998-07-01 01:22:38 +0000 |
commit | 7c6abaa1e636e549561370419dbb773190da5bf8 (patch) | |
tree | 694d0da85b0478c03a6331edf125234427825a64 /support | |
parent | f950762afbdd57a6974918a454c4df851e9086cc (diff) | |
download | shared-mime-info-7c6abaa1e636e549561370419dbb773190da5bf8.tar.gz |
Initial revision
svn path=/trunk/; revision=265
Diffstat (limited to 'support')
-rw-r--r-- | support/mkstemp.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/support/mkstemp.c b/support/mkstemp.c new file mode 100644 index 00000000..f0db5d5d --- /dev/null +++ b/support/mkstemp.c @@ -0,0 +1,90 @@ +/* Copyright (C) 1991, 1992, 1996, 1998 Free Software Foundation, Inc. + This file is part of 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <stdint.h> +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/time.h> + +/* Generate a unique temporary file name from TEMPLATE. + The last six characters of TEMPLATE must be "XXXXXX"; + they are replaced with a string that makes the filename unique. + Returns a file descriptor open on the file for reading and writing. */ +int +mkstemp (template) + char *template; +{ + static const char letters[] + = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; + static uint64_t value; + struct timeval tv; + char *XXXXXX; + size_t len; + int count; + + len = strlen (template); + if (len < 6 || strcmp (&template[len - 6], "XXXXXX")) + { + __set_errno (EINVAL); + return -1; + } + + /* This is where the Xs start. */ + XXXXXX = &template[len - 6]; + + /* Get some more or less random data. */ + __gettimeofday (&tv, NULL); + value += ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid (); + + for (count = 0; count < TMP_MAX; ++count) + { + 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 (template, O_RDWR|O_CREAT|O_EXCL, 0600); + if (fd >= 0) + /* The file does not exist. */ + return fd; + + /* 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. */ + template[0] = '\0'; + return -1; +} |