diff options
author | Marius Vollmer <mvo@zagadka.de> | 2001-06-02 12:39:09 +0000 |
---|---|---|
committer | Marius Vollmer <mvo@zagadka.de> | 2001-06-02 12:39:09 +0000 |
commit | 23cc59681bfcc239de26b9c1e526e5dede63a042 (patch) | |
tree | 8cbade05d8469625b93847de3bdc6dc29caae557 /libguile/mkstemp.c | |
parent | 26446f99071028b6aa9d87739f46311774f6ebbb (diff) | |
download | guile-23cc59681bfcc239de26b9c1e526e5dede63a042.tar.gz |
New file, slightly modified from libiberties
mkstemps.c.
Diffstat (limited to 'libguile/mkstemp.c')
-rw-r--r-- | libguile/mkstemp.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/libguile/mkstemp.c b/libguile/mkstemp.c new file mode 100644 index 000000000..a35f8d6d0 --- /dev/null +++ b/libguile/mkstemp.c @@ -0,0 +1,123 @@ +/* Copyright (C) 1991, 1992, 1996, 1998 Free Software Foundation, Inc. + This file is derived from mkstemps.c from the GNU Libiberty Library + which in turn is derived 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "scmconfig.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> +#endif + +/* We need to provide a type for gcc_uint64_t. */ +#ifdef __GNUC__ +typedef unsigned long long gcc_uint64_t; +#else +typedef unsigned long gcc_uint64_t; +#endif + +#ifndef TMP_MAX +#define TMP_MAX 16384 +#endif + +/* Generate a unique temporary file name from TEMPLATE. + + TEMPLATE has the form: + + <path>/ccXXXXXX + + 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 gcc_uint64_t value; +#ifdef HAVE_GETTIMEOFDAY + struct timeval tv; +#endif + char *XXXXXX; + size_t len; + int count; + + len = strlen (template); + + if ((int) len < 6 + || strncmp (&template[len - 6], "XXXXXX", 6)) + { + return -1; + } + + XXXXXX = &template[len - 6]; + +#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 (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; +} |