NT4/private/crt32/stdio/freopen.c
2020-09-30 17:12:29 +02:00

106 lines
2.5 KiB
C

/***
*freopen.c - close a stream and assign it to a new file
*
* Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines freopen() - close and reopen file, typically used to redirect
* stdin/out/err/prn/aux.
*
*Revision History:
* 09-02-83 RN initial version
* 04-13-87 JCR added const to declarations
* 11-02-87 JCR Multi-thread support
* 12-11-87 JCR Added "_LOAD_DS" to declaration
* 05-27-88 PHG Merged DLL and normal versions
* 06-15-88 JCR Near reference to _iob[] entries; improve REG variables
* 08-25-88 GJF Don't use FP_OFF() macro for the 386
* 11-14-88 GJF _openfile() now takes a file sharing flag, also some
* cleanup (now specific to the 386)
* 08-17-89 GJF Clean up, now specific to OS/2 2.0 (i.e., 386 flat
* model). Also fixed copyright and indents.
* 02-15-90 GJF Fixed copyright
* 03-19-90 GJF Made calling type _CALLTYPE1, added #include
* <cruntime.h> and removed #include <register.h>.
* 07-23-90 SBM Replaced <assertm.h> by <assert.h>
* 10-02-90 GJF New-style function declarator.
* 01-22-91 GJF ANSI naming.
* 03-27-92 DJM POSIX support.
*
*******************************************************************************/
#include <cruntime.h>
#include <stdio.h>
#include <file2.h>
#include <share.h>
#include <assert.h>
#include <internal.h>
#include <os2dll.h>
/***
*FILE *freopen(filename, mode, stream) - reopen stream as new file
*
*Purpose:
* Closes the file associated with stream and assigns stream to a new
* file with current mode. Usually used to redirect a standard file
* handle.
*
*Entry:
* char *filename - new file to open
* char *mode - new file mode, as in fopen()
* FILE *stream - stream to close and reassign
*
*Exit:
* returns stream if successful
* return NULL if fails
*
*Exceptions:
*
*******************************************************************************/
FILE * _CALLTYPE1 freopen (
const char *filename,
const char *mode,
FILE *str
)
{
REG1 FILE *stream;
FILE *retval;
#ifdef MTHREAD
int index;
#endif
assert(filename != NULL);
assert(*filename != '\0');
assert(mode != NULL);
assert(str != NULL);
/* Init stream pointer */
stream = str;
#ifdef MTHREAD
index = _iob_index(stream);
#endif
_lock_str(index);
if (inuse(stream) && _fclose_lk(stream) == EOF) {
retval = NULL;
goto done;
}
stream->_ptr = stream->_base = NULL;
stream->_cnt = stream->_flag = 0;
#ifdef _POSIX_
retval = _openfile(filename,mode,stream);
#else
retval = _openfile(filename,mode,_SH_DENYNO,stream);
#endif
/* Common return code */
done:
_unlock_str(index);
return(retval);
}