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Diffstat (limited to 'StdLib/LibC/Stdio/freopen.c')
| -rw-r--r-- | StdLib/LibC/Stdio/freopen.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/StdLib/LibC/Stdio/freopen.c b/StdLib/LibC/Stdio/freopen.c new file mode 100644 index 0000000000..186ab9ad66 --- /dev/null +++ b/StdLib/LibC/Stdio/freopen.c @@ -0,0 +1,196 @@ +/** @file
+ Implementation of freopen as declared in <stdio.h>.
+
+ Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License that accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+ Copyright (c) 1990, 1993
+ 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:
+ - Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ - 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.
+ - 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDERS 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.
+
+ NetBSD: freopen.c,v 1.14 2003/08/07 16:43:25 agc Exp
+ freopen.c 8.1 (Berkeley) 6/4/93
+**/
+#include <LibConfig.h>
+#include <sys/EfiCdefs.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/EfiSysCall.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include "reentrant.h"
+#include "local.h"
+
+/*
+ * 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(const char *file, const char *mode, FILE *fp)
+{
+ int f;
+ int flags, isopen, oflags, sverrno, wantfd;
+
+ _DIAGASSERT(file != NULL);
+ _DIAGASSERT(mode != NULL);
+ _DIAGASSERT(fp != NULL);
+
+ if ((flags = __sflags(mode, &oflags)) == 0) {
+ (void) fclose(fp);
+ return (NULL);
+ }
+
+ if (!__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.
+ */
+ if (fp->_flags == 0) {
+ fp->_flags = __SEOF; /* hold on to it */
+ isopen = 0;
+ wantfd = -1;
+ } else {
+ /* flush the stream; ANSI doesn't require this. */
+ if (fp->_flags & __SWR)
+ (void) __sflush(fp);
+ /* if close is NULL, closing is a no-op, hence pointless */
+ isopen = fp->_close != NULL;
+ if ((wantfd = fp->_file) < 0 && isopen) {
+ (void) (*fp->_close)(fp->_cookie);
+ isopen = 0;
+ }
+ }
+
+ /* 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) (*fp->_close)(fp->_cookie);
+ isopen = 0;
+ 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 && f != wantfd)
+ (void) (*fp->_close)(fp->_cookie);
+ 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);
+ WCIO_FREE(fp);
+ _UB(fp)._size = 0;
+ if (HASLB(fp))
+ FREELB(fp);
+ fp->_lb._size = 0;
+
+ if (f < 0) { /* did not get it after all */
+ fp->_flags = 0; /* set it free */
+ errno = sverrno; /* restore in case _close clobbered */
+ return (NULL);
+ }
+
+ if (oflags & O_NONBLOCK) {
+ struct stat st;
+ if (fstat(f, &st) == -1) {
+ sverrno = errno;
+ (void)close(f);
+ errno = sverrno;
+ return (NULL);
+ }
+ if (!S_ISREG(st.st_mode)) {
+ (void)close(f);
+ errno = EFTYPE;
+ return (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.
+ */
+ if (wantfd >= 0 && f != wantfd) {
+ if (dup2(f, wantfd) >= 0) {
+ (void) close(f);
+ f = wantfd;
+ }
+ }
+
+ fp->_flags = (unsigned short)flags;
+ fp->_file = (short)f;
+ fp->_cookie = fp;
+ fp->_read = __sread;
+ fp->_write = __swrite;
+ fp->_seek = __sseek;
+ fp->_close = __sclose;
+
+ /*
+ * When reopening in append mode, even though we use O_APPEND,
+ * we need to seek to the end so that ftell() gets the right
+ * answer. If the user then alters the seek pointer, or
+ * the file extends, this will fail, but there is not much
+ * we can do about this. (We could set __SAPP and check in
+ * fseek and ftell.)
+ */
+ if (oflags & O_APPEND)
+ (void) __sseek((void *)fp, (fpos_t)0, SEEK_END);
+ return (fp);
+}
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