147 lines
4.9 KiB
C
147 lines
4.9 KiB
C
/*-
|
|
* Copyright (c) 1990 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Chris Torek.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
/*static char *sccsid = "from: @(#)freopen.c 5.6 (Berkeley) 2/24/91";*/
|
|
static char *rcsid = "$Id: freopen.c,v 1.1 1994/02/07 22:05:56 proven Exp $";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <pthread.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include "local.h"
|
|
|
|
extern pthread_mutex_t __sfp_mutex;
|
|
extern pthread_cond_t __sfp_cond;
|
|
extern int __sfp_state;
|
|
|
|
/*
|
|
* Re-direct an existing, open (probably) file to some other file.
|
|
* ANSI is written such that the original file gets closed if at
|
|
* all possible, no matter what.
|
|
*/
|
|
FILE *
|
|
freopen(file, mode, fp)
|
|
const char *file, *mode;
|
|
register FILE *fp;
|
|
{
|
|
int f, flags, oflags;
|
|
FILE *ret;
|
|
|
|
if ((flags = __sflags(mode, &oflags)) == 0) {
|
|
(void) fclose(fp);
|
|
return (NULL);
|
|
}
|
|
|
|
pthread_once(&__sdidinit, __sinit);
|
|
|
|
/*
|
|
* There are actually programs that depend on being able to "freopen"
|
|
* descriptors that weren't originally open. Keep this from breaking.
|
|
* Remember whether the stream was open to begin with, and which file
|
|
* descriptor (if any) was associated with it. If it was attached to
|
|
* a descriptor, defer closing it; freopen("/dev/stdin", "r", stdin)
|
|
* should work. This is unnecessary if it was not a Unix file.
|
|
*/
|
|
/* while lock __sfp_mutex, to block out fopen, and other freopen calls */
|
|
while (pthread_mutex_lock(&__sfp_mutex) == OK) {
|
|
if (ftrylockfile(fp) == OK) {
|
|
if (fp->_flags) {
|
|
/* flush the stream; ANSI doesn't require this. */
|
|
if (fp->_flags & __SWR)
|
|
(void) __sflush(fp);
|
|
__sclose(fp);
|
|
/*
|
|
* Finish closing fp. We cannot keep fp->_base:
|
|
* it may be the wrong size. This loses the effect
|
|
* of any setbuffer calls, but stdio has always done
|
|
* this before.
|
|
* NOTE: We do this even if __ftrylockfilr failed with
|
|
* an error to avoid memory leaks.
|
|
*/
|
|
if (fp->_flags & __SMBF)
|
|
free((char *)fp->_bf._base);
|
|
fp->_w = 0;
|
|
fp->_r = 0;
|
|
fp->_p = NULL;
|
|
fp->_bf._base = NULL;
|
|
fp->_bf._size = 0;
|
|
fp->_lbfsize = 0;
|
|
if (HASUB(fp))
|
|
FREEUB(fp);
|
|
fp->_ub._size = 0;
|
|
if (HASLB(fp))
|
|
FREELB(fp);
|
|
fp->_lb._size = 0;
|
|
}
|
|
/* Get a new descriptor to refer to the new file. */
|
|
if ((f = open(file, oflags, 0666)) < OK)
|
|
ret = NULL;
|
|
/*
|
|
* If reopening something that was open before on a real file, try
|
|
* to maintain the descriptor. Various C library routines (perror)
|
|
* assume stderr is always fd STDERR_FILENO, even if being freopen'd.
|
|
*/
|
|
/* Testing f == fp->_file may no longer be necessary */
|
|
if (fp->_file >= 0 && f != fp->_file) {
|
|
if (dup2(f, fp->_file) >= OK) {
|
|
(void)close(f);
|
|
f = fp->_file;
|
|
}
|
|
}
|
|
fp->_flags = flags;
|
|
fp->_file = f;
|
|
ret = fp;
|
|
break;
|
|
} else {
|
|
/* unlock __sfp_mutex, and try again later */
|
|
pthread_mutex_unlock(&__sfp_mutex);
|
|
pthread_yield();
|
|
continue;
|
|
}
|
|
pthread_mutex_unlock(&__sfp_mutex);
|
|
funlockfile(fp);
|
|
return(ret);
|
|
}
|
|
(void)fclose(fp);
|
|
return(NULL);
|
|
}
|