/* freopen.c - reopen a file. stdio.h */ /* Copyright 1992-1993 Wind River Systems, Inc. */ /* modification history -------------------- 01c,05mar93,jdi documentation cleanup for 5.1. 01b,20sep92,smb documentation additions 01a,29jul92,jcf added memory reclaimation. +smb taken from UCB stdio */ /* DESCRIPTION * 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. INCLUDE FILE: stdio.h, sys/types.h, sys/stat.h, fcntl.h, error.h, unistd.h, stdlib.h SEE ALSO: American National Standard X3.159-1989 NOMANUAL */ #include "vxWorks.h" #include "stdio.h" #include "ioLib.h" #include "sys/types.h" #include "sys/stat.h" #include "fcntl.h" #include "errno.h" #include "unistd.h" #include "stdlib.h" #include "objLib.h" #include "private/stdioP.h" /****************************************************************************** * * freopen - open a file specified by name (ANSI) * * This routine opens a file whose name is the string pointed to by * and associates it with a specified stream . * The argument is used just as in the fopen() function. * * This routine first attempts to close any file that is associated * with the specified stream. Failure to close the file successfully is * ignored. The error and end-of-file indicators for the stream are cleared. * * Typically, freopen() is used to attach the already-open streams * `stdin', `stdout', and `stderr' to other files. * * INCLUDE FILES: stdio.h * * RETURNS: * The value of , or a null pointer if the open operation fails. * * SEE ALSO: fopen() */ FILE * freopen ( const char * file, /* name of file */ const char * mode, /* mode */ FAST FILE * fp /* stream */ ) { FAST int f; int flags; int oflags; int sverrno; BOOL isopen = TRUE; /* its already open */ if (OBJ_VERIFY (fp, fpClassId) != OK) return (NULL); if ((flags = __sflags (mode, &oflags)) == 0) { (void) fclose (fp); return (NULL); } /* * 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. */ if (fp->_flags & __SWR) /* flush the stream though */ (void) __sflush(fp); /* ANSI doesn't require this */ if (fp->_file < 0) /* need to close the fp? */ { (void) __sclose (fp); isopen = FALSE; } /* Get a new descriptor to refer to the new file. */ f = open (file, oflags, DEFFILEMODE); if ((f < 0) && isopen) { /* If out of fd's close the old one and try again. */ if ((errno == ENFILE) || (errno == EMFILE)) { (void) __sclose (fp); isopen = FALSE; f = open (file, oflags, DEFFILEMODE); } } sverrno = errno; /* * Finish closing fp. Even if the open succeeded above, 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. */ if (isopen) (void) __sclose (fp); 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; if ((f < 0) && (fp->_flags != 0)) { /* did not get it after all */ fp->_flags = 0; /* set it free */ stdioFpDestroy (fp); /* destroy file pointer */ errno = sverrno; /* restore in case _close clobbered */ return (NULL); } fp->_flags = flags; fp->_file = f; return (fp); }
