128 lines
3.3 KiB
C
128 lines
3.3 KiB
C
/* Copyright (C) 1991, 1992, 1996, 1998 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., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#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
|
|
#include "ansidecl.h"
|
|
|
|
/* 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<suffix>
|
|
|
|
SUFFIX_LEN tells us how long <suffix> is (it can be zero length).
|
|
|
|
The last six characters of TEMPLATE before <suffix> 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
|
|
mkstemps (template, suffix_len)
|
|
char *template;
|
|
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 (template);
|
|
|
|
if ((int) len < 6 + suffix_len
|
|
|| strncmp (&template[len - 6 - suffix_len], "XXXXXX", 6))
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
XXXXXX = &template[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 (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;
|
|
}
|