windows-nt/Source/XPSP1/NT/base/crts/crtw32/stdio/tmpfile.c

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2020-09-26 03:20:57 -05:00
/***
*tmpfile.c - create unique file name or file
*
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines tmpnam() and tmpfile().
*
*Revision History:
* ??-??-?? TC initial version
* 04-17-86 JMB tmpnam - brought semantics in line with System V
* definition as follows: 1) if tmpnam paramter is NULL,
* store name in static buffer (do NOT use malloc); (2)
* use P_tmpdir as the directory prefix to the temp file
* name (do NOT use current working directory)
* 05-26-87 JCR fixed bug where tmpnam was modifying errno
* 08-10-87 JCR Added code to support P_tmpdir with or without trailing
* '\'.
* 11-09-87 JCR Multi-thread support
* 12-11-87 JCR Added "_LOAD_DS" to declaration
* 01-22-88 JCR Added per thread static namebuf area (mthread bug fix)
* 05-27-88 PHG Merged DLL/normal versions
* 11-14-88 GJF _openfile() now takes a file sharing flag, also some
* cleanup (now specific to the 386)
* 06-06-89 JCR 386 mthread support
* 11-28-89 JCR Added check to _tmpnam so it can't loop forever
* 02-16-90 GJF Fixed copyright and indents
* 03-19-90 GJF Replaced _LOAD_DS with _CALLTYPE1, added #include
* <cruntime.h> and removed #include <register.h>.
* 03-26-90 GJF Added #include <io.h>.
* 10-03-90 GJF New-style function declarators.
* 01-21-91 GJF ANSI naming.
* 07-22-91 GJF Multi-thread support for Win32 [_WIN32_].
* 03-17-92 GJF Completely rewrote Win32 version.
* 03-27-92 DJM POSIX support.
* 05-02-92 SRW Use _O_TEMPORARY flag for tmpfile routine.
* 05-04-92 GJF Force cinittmp.obj in for Win32.
* 08-26-92 GJF Fixed POSIX build.
* 08-28-92 GJF Oops, forgot about getpid...
* 11-06-92 GJF Use '/' for POSIX, '\\' otherwise, as the path
* separator. Also, backed out JHavens' bug fix of 6-14,
* which was itself a bug (albeit a less serious one).
* 02-26-93 GJF Put in per-thread buffers, purged Cruiser support.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 04-07-93 SKS Replace access() with ANSI-conforming _access()
* 04-22-93 GJF Fixed bug in multi-thread - multiple threads calling
* tmpnam would get the same names. Also, went to static
* namebufX buffers since failing due to a failed malloc
* would violate ANSI.
* 04-29-93 GJF Multi-thread bug in tmpnam() - forgot to copy the
* generated name to the per-thread buffer.
* 12-07-93 CFW Wide char enable.
* 04-01-94 GJF #ifdef-ed out __inc_tmpoff for msvcrt*.dll, it's
* unnecessary.
* 04-22-94 GJF Made definitions of namebuf0 and namebuf1 conditional
* on DLL_FOR_WIN32S.
* 01-10-95 CFW Debug CRT allocs.
* 01-18-95 GJF Must replace _tcsdup with _malloc_crt/_tcscpy for
* _DEBUG build.
* 02-21-95 GJF Appended Mac version of source file (somewhat cleaned
* up), with appropriate #ifdef-s. Also replaced WPRFLAG
* with _UNICODE.
* 03-07-95 GJF _[un]lock_str macros now take FILE * arg.
* 08-08-97 GJF Removed initialized-but-unused local variable from
* tmpfile(). Also, detab-ed.
* 03-03-98 GJF Exception-safe locking.
* 05-13-99 PML Remove Win32s
* 05-17-99 PML Remove all Macintosh support.
* 10-06-99 PML Set errno EMFILE when out of streams.
* 07-03-01 BWT Fix genfname to use the correct buffer size to encode a dword (7 bytes + NULL).
*
*******************************************************************************/
#include <cruntime.h>
#ifdef _POSIX_
#include <unistd.h>
#endif
#include <errno.h>
#include <process.h>
#include <fcntl.h>
#include <io.h>
#include <mtdll.h>
#include <share.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <file2.h>
#include <internal.h>
#include <tchar.h>
#include <dbgint.h>
/*
* Buffers used by tmpnam() and tmpfile() to build filenames.
*/
static _TSCHAR namebuf0[L_tmpnam] = { 0 }; /* used by tmpnam() */
static _TSCHAR namebuf1[L_tmpnam] = { 0 }; /* used by tmpfile() */
/*
* Initializing function for namebuf0 and namebuf1.
*/
#ifdef _UNICODE
static void __cdecl winit_namebuf(int);
#else
static void __cdecl init_namebuf(int);
#endif
/*
* Generator function that produces temporary filenames
*/
#ifdef _UNICODE
static int __cdecl wgenfname(wchar_t *);
#else
static int __cdecl genfname(char *);
#endif
/***
*_TSCHAR *tmpnam(_TSCHAR *s) - generate temp file name
*
*Purpose:
* Creates a file name that is unique in the directory specified by
* _P_tmpdir in stdio.h. Places file name in string passed by user or
* in static mem if pass NULL.
*
*Entry:
* _TSCHAR *s - ptr to place to put temp name
*
*Exit:
* returns pointer to constructed file name (s or address of static mem)
* returns NULL if fails
*
*Exceptions:
*
*******************************************************************************/
_TSCHAR * __cdecl _ttmpnam (
_TSCHAR *s
)
{
_TSCHAR *pfnam = NULL;
#ifdef _MT
_ptiddata ptd;
if ( !_mtinitlocknum( _TMPNAM_LOCK ))
return NULL;
_mlock(_TMPNAM_LOCK);
__try {
#endif
/*
* Initialize namebuf0, if needed. Otherwise, call genfname() to
* generate the next filename.
*/
if ( *namebuf0 == 0 ) {
#ifdef _UNICODE
winit_namebuf(0);
#else
init_namebuf(0);
#endif
}
#ifdef _UNICODE
else if ( wgenfname(namebuf0) )
#else
else if ( genfname(namebuf0) )
#endif
goto tmpnam_err;
/*
* Generate a filename that doesn't already exist.
*/
while ( _taccess(namebuf0, 0) == 0 )
#ifdef _UNICODE
if ( wgenfname(namebuf0) )
#else
if ( genfname(namebuf0) )
#endif
goto tmpnam_err;
/*
* Filename has successfully been generated.
*/
if ( s == NULL )
#ifdef _MT
{
/*
* Use a per-thread buffer to hold the generated file name.
* If there isn't one, and one cannot be created, just use
* namebuf0.
*/
ptd = _getptd();
#ifdef _UNICODE
if ( (ptd->_wnamebuf0 != NULL) || ((ptd->_wnamebuf0 =
_malloc_crt(L_tmpnam * sizeof(wchar_t))) != NULL) )
{
s = ptd->_wnamebuf0;
wcscpy(s, namebuf0);
}
#else
if ( (ptd->_namebuf0 != NULL) || ((ptd->_namebuf0 =
_malloc_crt(L_tmpnam)) != NULL) )
{
s = ptd->_namebuf0;
strcpy(s, namebuf0);
}
#endif
else
s = namebuf0;
}
#else
s = namebuf0;
#endif
else
_tcscpy(s, namebuf0);
pfnam = s;
/*
* All errors come here.
*/
tmpnam_err:
#ifdef _MT
; }
__finally {
_munlock(_TMPNAM_LOCK);
}
#endif
return pfnam;
}
#ifndef _UNICODE
/***
*FILE *tmpfile() - create a temporary file
*
*Purpose:
* Creates a temporary file with the file mode "w+b". The file
* will be automatically deleted when closed or the program terminates
* normally.
*
*Entry:
* None.
*
*Exit:
* Returns stream pointer to opened file.
* Returns NULL if fails
*
*Exceptions:
*
*******************************************************************************/
FILE * __cdecl tmpfile (
void
)
{
FILE *stream;
FILE *return_stream = NULL;
int fh;
#ifdef _MT
int stream_lock_held = 0;
if ( !_mtinitlocknum( _TMPNAM_LOCK ))
return NULL;
_mlock(_TMPNAM_LOCK);
__try {
#endif
/*
* Initialize namebuf1, if needed. Otherwise, call genfname() to
* generate the next filename.
*/
if ( *namebuf1 == 0 ) {
init_namebuf(1);
}
else if ( genfname(namebuf1) )
goto tmpfile_err;
/*
* Get a free stream.
*
* Note: In multi-thread models, the stream obtained below is locked!
*/
if ( (stream = _getstream()) == NULL ) {
errno = EMFILE;
goto tmpfile_err;
}
#ifdef _MT
stream_lock_held = 1;
#endif
/*
* Create a temporary file.
*
* Note: The loop below will only create a new file. It will NOT
* open and truncate an existing file. Either behavior is probably
* legal under ANSI (4.9.4.3 says tmpfile "creates" the file, but
* also says it is opened with mode "wb+"). However, the behavior
* implemented below is compatible with prior versions of MS-C and
* makes error checking easier.
*/
#ifdef _POSIX_
while ( ((fh = open(namebuf1,
O_CREAT | O_EXCL | O_RDWR,
S_IRUSR | S_IWUSR
))
== -1) && (errno == EEXIST) )
#else
while ( ((fh = _sopen(namebuf1,
_O_CREAT | _O_EXCL | _O_RDWR | _O_BINARY |
_O_TEMPORARY,
_SH_DENYNO,
_S_IREAD | _S_IWRITE
))
== -1) && (errno == EEXIST) )
#endif
if ( genfname(namebuf1) )
break;
/*
* Check that the loop above did indeed create a temporary
* file.
*/
if ( fh == -1 )
goto tmpfile_err;
/*
* Initialize stream
*/
#ifdef _DEBUG
if ( (stream->_tmpfname = _malloc_crt( (_tcslen( namebuf1 ) + 1) *
sizeof(_TSCHAR) )) == NULL )
#else /* ndef _DEBUG */
if ( (stream->_tmpfname = _tcsdup( namebuf1 )) == NULL )
#endif /* _DEBUG */
{
/* close the file, then branch to error handling */
#ifdef _POSIX_
close(fh);
#else
_close(fh);
#endif
goto tmpfile_err;
}
#ifdef _DEBUG
_tcscpy( stream->_tmpfname, namebuf1 );
#endif /* _DEBUG */
stream->_cnt = 0;
stream->_base = stream->_ptr = NULL;
stream->_flag = _commode | _IORW;
stream->_file = fh;
return_stream = stream;
/*
* All errors branch to the label below.
*/
tmpfile_err:
#ifdef _MT
; }
__finally {
if ( stream_lock_held )
_unlock_str(stream);
_munlock(_TMPNAM_LOCK);
}
#endif
return return_stream;
}
#endif /* _UNICODE */
/***
*static void init_namebuf(flag) - initializes the namebuf arrays
*
*Purpose:
* Called once each for namebuf0 and namebuf1, to initialize
* them.
*
*Entry:
* int flag - flag set to 0 if namebuf0 is to be initialized,
* non-zero (1) if namebuf1 is to be initialized.
*Exit:
*
*Exceptions:
*
*******************************************************************************/
#ifdef _UNICODE
static void __cdecl winit_namebuf(
#else
static void __cdecl init_namebuf(
#endif
int flag
)
{
_TSCHAR *p, *q;
if ( flag == 0 )
p = namebuf0;
else
p = namebuf1;
/*
* Put in the path prefix. Make sure it ends with a slash or
* backslash character.
*/
#ifdef _UNICODE
wcscpy(p, _wP_tmpdir);
#else
strcpy(p, _P_tmpdir);
#endif
q = p + sizeof(_P_tmpdir) - 1; /* same as p + _tcslen(p) */
#ifdef _POSIX_
if ( *(q - 1) != _T('/') )
*(q++) = _T('/');
#else
if ( (*(q - 1) != _T('\\')) && (*(q - 1) != _T('/')) )
*(q++) = _T('\\');
#endif
/*
* Append the leading character of the filename.
*/
if ( flag )
/* for tmpfile() */
*(q++) = _T('t');
else
/* for tmpnam() */
*(q++) = _T('s');
/*
* Append the process id, encoded in base 32. Note this makes
* p back into a string again (i.e., terminated by a '\0').
*/
#ifdef _POSIX_
_ultot((unsigned long)getpid(), q, 32);
#else
_ultot((unsigned long)_getpid(), q, 32);
#endif
_tcscat(p, _T("."));
}
/***
*static int genfname(_TSCHAR *fname) -
*
*Purpose:
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/
#ifdef _UNICODE
static int __cdecl wgenfname (
#else
static int __cdecl genfname (
#endif
_TSCHAR *fname
)
{
_TSCHAR *p;
_TSCHAR pext[8]; // 7 positions for base 32 ulong + null terminator
unsigned long extnum;
p = _tcsrchr(fname, _T('.'));
p++;
if ( (extnum = _tcstoul(p, NULL, 32) + 1) >= (unsigned long)TMP_MAX )
return -1;
_tcscpy(p, _ultot(extnum, pext, 32));
return 0;
}
#if !defined(_UNICODE) && !defined(CRTDLL)
/***
*void __inc_tmpoff(void) - force external reference for _tmpoff
*
*Purpose:
* Forces an external reference to be generate for _tmpoff, which is
* is defined in cinittmp.obj. This has the forces cinittmp.obj to be
* pulled in, making a call to rmtmp part of the termination.
*
*Entry:
*
*Exit:
*
*Exceptions:
*
*******************************************************************************/
extern int _tmpoff;
void __inc_tmpoff(
void
)
{
_tmpoff++;
}
#endif /* _UNICODE */