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/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
#include "mysys_priv.h"
#include <m_string.h>
#include "my_static.h"
#include "mysys_err.h"
#include <errno.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
#ifdef HAVE_MKOSTEMP
#define mkstemp(A) mkostemp(A, O_CLOEXEC)
#endif
/*
@brief
Create a temporary file with unique name in a given directory
@details
create_temp_file
to pointer to buffer where temporary filename will be stored
dir directory where to create the file
prefix prefix the filename with this
mode Flags to use for my_create/my_open
MyFlags Magic flags
@return
File descriptor of opened file if success
-1 and sets errno if fails.
@note
The behaviour of this function differs a lot between
implementation, it's main use is to generate a file with
a name that does not already exist.
When passing MY_TEMPORARY flag in MyFlags the file is automatically deleted
"mode" bits that always must be used for newly created files with
unique file names (O_EXCL | O_TRUNC | O_CREAT | O_RDWR) are added
automatically, and shouldn't be specified by the caller.
The implementation using mkstemp should be considered the
reference implementation when adding a new or modifying an
existing one
*/
File create_temp_file(char *to, const char *dir, const char *prefix,
int mode, myf MyFlags)
{
File file= -1;
DBUG_ENTER("create_temp_file");
DBUG_PRINT("enter", ("dir: %s, prefix: %s", dir ? dir : "(null)", prefix));
DBUG_ASSERT((mode & (O_EXCL | O_TRUNC | O_CREAT | O_RDWR)) == 0);
mode|= O_TRUNC | O_CREAT | O_RDWR; /* not O_EXCL, see Windows code below */
#ifdef _WIN32
{
TCHAR path_buf[MAX_PATH-14];
/*
Use GetTempPath to determine path for temporary files.
This is because the documentation for GetTempFileName
has the following to say about this parameter:
"If this parameter is NULL, the function fails."
*/
if (!dir)
{
if(GetTempPath(sizeof(path_buf), path_buf) > 0)
dir = path_buf;
}
/*
Use GetTempFileName to generate a unique filename, create
the file and release it's handle
- uses up to the first three letters from prefix
*/
if (GetTempFileName(dir, prefix, 0, to) == 0)
DBUG_RETURN(-1);
DBUG_PRINT("info", ("name: %s", to));
if (MyFlags & MY_TEMPORARY)
mode|= O_SHORT_LIVED | O_TEMPORARY;
/*
Open the file without O_EXCL flag
since the file has already been created by GetTempFileName
*/
if ((file= my_open(to, mode, MyFlags)) < 0)
{
/* Open failed, remove the file created by GetTempFileName */
int tmp= my_errno;
(void) my_delete(to, MYF(0));
my_errno= tmp;
}
}
#elif defined(HAVE_MKSTEMP)
if (!dir && ! (dir =getenv("TMPDIR")))
dir= DEFAULT_TMPDIR;
#ifdef O_TMPFILE
{
static int O_TMPFILE_works= 1;
if ((MyFlags & MY_TEMPORARY) && O_TMPFILE_works)
{
/* explictly don't use O_EXCL here has it has a different
meaning with O_TMPFILE
*/
if ((file= open(dir, mode | O_TMPFILE | O_CLOEXEC,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP)) >= 0)
{
my_snprintf(to, FN_REFLEN, "%s/#sql/fd=%d", dir, file);
file=my_register_filename(file, to, FILE_BY_O_TMPFILE,
EE_CANTCREATEFILE, MyFlags);
}
else if (errno == EOPNOTSUPP || errno == EINVAL)
{
my_printf_error(EE_CANTCREATEFILE, "O_TMPFILE is not supported on %s "
"(disabling future attempts)",
MYF(ME_NOTE | ME_ERROR_LOG_ONLY), dir);
O_TMPFILE_works= 0;
}
}
}
if (file == -1)
#endif /* O_TMPFILE */
{
char prefix_buff[30];
uint pfx_len;
File org_file;
pfx_len= (uint) (strmov(strnmov(prefix_buff,
prefix ? prefix : "tmp.",
sizeof(prefix_buff)-7),"XXXXXX") -
prefix_buff);
if (strlen(dir)+ pfx_len > FN_REFLEN-2)
{
errno=my_errno= ENAMETOOLONG;
DBUG_RETURN(file);
}
strmov(convert_dirname(to,dir,NullS),prefix_buff);
org_file=mkstemp(to);
if (org_file >= 0 && (MyFlags & MY_TEMPORARY))
(void) my_delete(to, MYF(MY_WME));
file=my_register_filename(org_file, to, FILE_BY_MKSTEMP,
EE_CANTCREATEFILE, MyFlags);
/* If we didn't manage to register the name, remove the temp file */
if (org_file >= 0 && file < 0)
{
int tmp=my_errno;
close(org_file);
(void) my_delete(to, MYF(MY_WME));
my_errno=tmp;
}
}
#else
#error No implementation found for create_temp_file
#endif
if (file >= 0)
statistic_increment(my_tmp_file_created,&THR_LOCK_open);
DBUG_RETURN(file);
}
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