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/* Utility to pick a temporary filename prefix.
Copyright (C) 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
This file is part of the libiberty library.
Libiberty 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.
Libiberty is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with libiberty; 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 "config.h"
#include <stdio.h> /* May get P_tmpdir. */
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h> /* May get R_OK, etc. on some systems. */
#ifndef R_OK
#define R_OK 4
#define W_OK 2
#define X_OK 1
#include "libiberty.h"
extern int mkstemps PARAMS ((char *, int));
/* '/' works just fine on MS-DOS based systems. */
#define DIR_SEPARATOR '/'
/* Name of temporary file.
mktemp requires 6 trailing X's. */
#define TEMP_FILE "ccXXXXXX"
#define TEMP_FILE_LEN (sizeof(TEMP_FILE) - 1)
/* Subroutine of choose_tmpdir.
If BASE is non-NULL, return it.
Otherwise it checks if DIR is a usable directory.
If success, DIR is returned.
Otherwise NULL is returned. */
static inline const char *try PARAMS ((const char *, const char *));
static inline const char *
try (dir, base)
const char *dir, *base;
if (base != 0)
return base;
if (dir != 0
&& access (dir, R_OK | W_OK | X_OK) == 0)
return dir;
return 0;
static const char tmp[] = { DIR_SEPARATOR, 't', 'm', 'p', 0 };
static const char usrtmp[] =
{ DIR_SEPARATOR, 'u', 's', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 };
static const char vartmp[] =
{ DIR_SEPARATOR, 'v', 'a', 'r', DIR_SEPARATOR, 't', 'm', 'p', 0 };
static char *memoized_tmpdir;
@deftypefn Replacement char* choose_tmpdir ()
Returns a pointer to a directory path suitable for creating temporary
files in.
@end deftypefn
char *
choose_tmpdir ()
const char *base = 0;
char *tmpdir;
unsigned int len;
if (memoized_tmpdir)
return memoized_tmpdir;
base = try (getenv ("TMPDIR"), base);
base = try (getenv ("TMP"), base);
base = try (getenv ("TEMP"), base);
#ifdef P_tmpdir
base = try (P_tmpdir, base);
/* Try /var/tmp, /usr/tmp, then /tmp. */
base = try (vartmp, base);
base = try (usrtmp, base);
base = try (tmp, base);
/* If all else fails, use the current directory! */
if (base == 0)
base = ".";
/* Append DIR_SEPARATOR to the directory we've chosen
and return it. */
len = strlen (base);
tmpdir = xmalloc (len + 2);
strcpy (tmpdir, base);
tmpdir[len] = DIR_SEPARATOR;
tmpdir[len+1] = '\0';
memoized_tmpdir = tmpdir;
return tmpdir;
@deftypefn Replacement char* make_temp_file (const char *@var{suffix})
Return a temporary file name (as a string) or @code{NULL} if unable to
create one. @var{suffix} is a suffix to append to the file name. The
string is @code{malloc}ed, and the temporary file has been created.
@end deftypefn
char *
make_temp_file (suffix)
const char *suffix;
const char *base = choose_tmpdir ();
char *temp_filename;
int base_len, suffix_len;
int fd;
if (suffix == 0)
suffix = "";
base_len = strlen (base);
suffix_len = strlen (suffix);
temp_filename = xmalloc (base_len
+ suffix_len + 1);
strcpy (temp_filename, base);
strcpy (temp_filename + base_len, TEMP_FILE);
strcpy (temp_filename + base_len + TEMP_FILE_LEN, suffix);
fd = mkstemps (temp_filename, suffix_len);
/* If mkstemps failed, then something bad is happening. Maybe we should
issue a message about a possible security attack in progress? */
if (fd == -1)
abort ();
/* Similarly if we can not close the file. */
if (close (fd))
abort ();
return temp_filename;