newlib-cygwin/newlib/libc/stdio/ungetc.c

218 lines
5.7 KiB
C
Raw Normal View History

2000-02-18 03:39:52 +08:00
/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/*
FUNCTION
<<ungetc>>---push data back into a stream
INDEX
ungetc
INDEX
_ungetc_r
ANSI_SYNOPSIS
#include <stdio.h>
int ungetc(int <[c]>, FILE *<[stream]>);
int _ungetc_r(struct _reent *<[reent]>, int <[c]>, FILE *<[stream]>);
DESCRIPTION
<<ungetc>> is used to return bytes back to <[stream]> to be read again.
If <[c]> is EOF, the stream is unchanged. Otherwise, the unsigned
char <[c]> is put back on the stream, and subsequent reads will see
the bytes pushed back in reverse order. Pushed byes are lost if the
stream is repositioned, such as by <<fseek>>, <<fsetpos>>, or
<<rewind>>.
The underlying file is not changed, but it is possible to push back
something different than what was originally read. Ungetting a
character will clear the end-of-stream marker, and decrement the file
position indicator. Pushing back beyond the beginning of a file gives
unspecified behavior.
The alternate function <<_ungetc_r>> is a reentrant version. The
extra argument <[reent]> is a pointer to a reentrancy structure.
RETURNS
The character pushed back, or <<EOF>> on error.
PORTABILITY
ANSI C requires <<ungetc>>, but only requires a pushback buffer of one
byte; although this implementation can handle multiple bytes, not all
can. Pushing back a signed char is a common application bug.
Supporting OS subroutines required: <<sbrk>>.
*/
2000-02-18 03:39:52 +08:00
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "%W% (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
2004-04-23 Artem B. Bityuckiy <abitytsky@softminecorp.com> * libc/stdio/asprintf.c libc/stdio/clearerr.c, libc/stdio/fclose.c libc/stdio/fcloseall.c libc/stdio/fdopen.c, libc/stdio/feof.c libc/stdio/ferror.c libc/stdio/fflush.c, libc/stdio/fgetc.c libc/stdio/fgetpos.c libc/stdio/fgets.c, libc/stdio/fileno.c libc/stdio/findfp.c libc/stdio/fiprintf.c, libc/stdio/flags.c libc/stdio/fopen.c libc/stdio/fprintf.c, libc/stdio/fputc.c libc/stdio/fputs.c libc/stdio/fread.c, libc/stdio/freopen.c libc/stdio/fscanf.c libc/stdio/fseek.c, libc/stdio/fseeko.c libc/stdio/fsetpos.c libc/stdio/ftell.c, libc/stdio/ftello.c libc/stdio/fvwrite.c libc/stdio/fwalk.c, libc/stdio/fwrite.c libc/stdio/getc.c libc/stdio/getc_u.c, libc/stdio/getchar.c libc/stdio/getchar_u.c, libc/stdio/getdelim.c libc/stdio/getline.c libc/stdio/gets.c, libc/stdio/getw.c libc/stdio/iprintf.c libc/stdio/local.h, libc/stdio/makebuf.c libc/stdio/mktemp.c libc/stdio/perror.c, libc/stdio/printf.c libc/stdio/putc.c libc/stdio/putc_u.c, libc/stdio/putchar.c libc/stdio/putchar_u.c libc/stdio/puts.c, libc/stdio/putw.c libc/stdio/refill.c libc/stdio/remove.c, libc/stdio/rename.c libc/stdio/rewind.c libc/stdio/rget.c, libc/stdio/scanf.c libc/stdio/setbuf.c libc/stdio/setbuffer.c, libc/stdio/setlinebuf.c libc/stdio/setvbuf.c, libc/stdio/siprintf.c libc/stdio/snprintf.c, libc/stdio/sprintf.c libc/stdio/sscanf.c libc/stdio/stdio.c, libc/stdio/tmpfile.c libc/stdio/tmpnam.c libc/stdio/ungetc.c, libc/stdio/vasprintf.c libc/stdio/vfieeefp.h, libc/stdio/vfprintf.c libc/stdio/vfscanf.c, libc/stdio/vprintf.c libc/stdio/vscanf.c, libc/stdio/vsnprintf.c libc/stdio/vsprintf.c, libc/stdio/vsscanf.c libc/stdio/wbuf.c, libc/stdio/wsetup.c: Perform minor formatting changes. Move copyright notices to top of file, ensure that <_ansi.h> is included, be consistent with open parentheses, use _DEFUN macro, include "local.h" where needed, and remove various compiler warnings.
2004-04-24 04:01:55 +08:00
#include <_ansi.h>
#include <reent.h>
2000-02-18 03:39:52 +08:00
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "local.h"
/*
* Expand the ungetc buffer `in place'. That is, adjust fp->_p when
* the buffer moves, so that it points the same distance from the end,
* and move the bytes in the buffer around as necessary so that they
* are all at the end (stack-style).
*/
/*static*/
int
_DEFUN(__submore, (rptr, fp),
struct _reent *rptr _AND
2004-04-23 Artem B. Bityuckiy <abitytsky@softminecorp.com> * libc/stdio/asprintf.c libc/stdio/clearerr.c, libc/stdio/fclose.c libc/stdio/fcloseall.c libc/stdio/fdopen.c, libc/stdio/feof.c libc/stdio/ferror.c libc/stdio/fflush.c, libc/stdio/fgetc.c libc/stdio/fgetpos.c libc/stdio/fgets.c, libc/stdio/fileno.c libc/stdio/findfp.c libc/stdio/fiprintf.c, libc/stdio/flags.c libc/stdio/fopen.c libc/stdio/fprintf.c, libc/stdio/fputc.c libc/stdio/fputs.c libc/stdio/fread.c, libc/stdio/freopen.c libc/stdio/fscanf.c libc/stdio/fseek.c, libc/stdio/fseeko.c libc/stdio/fsetpos.c libc/stdio/ftell.c, libc/stdio/ftello.c libc/stdio/fvwrite.c libc/stdio/fwalk.c, libc/stdio/fwrite.c libc/stdio/getc.c libc/stdio/getc_u.c, libc/stdio/getchar.c libc/stdio/getchar_u.c, libc/stdio/getdelim.c libc/stdio/getline.c libc/stdio/gets.c, libc/stdio/getw.c libc/stdio/iprintf.c libc/stdio/local.h, libc/stdio/makebuf.c libc/stdio/mktemp.c libc/stdio/perror.c, libc/stdio/printf.c libc/stdio/putc.c libc/stdio/putc_u.c, libc/stdio/putchar.c libc/stdio/putchar_u.c libc/stdio/puts.c, libc/stdio/putw.c libc/stdio/refill.c libc/stdio/remove.c, libc/stdio/rename.c libc/stdio/rewind.c libc/stdio/rget.c, libc/stdio/scanf.c libc/stdio/setbuf.c libc/stdio/setbuffer.c, libc/stdio/setlinebuf.c libc/stdio/setvbuf.c, libc/stdio/siprintf.c libc/stdio/snprintf.c, libc/stdio/sprintf.c libc/stdio/sscanf.c libc/stdio/stdio.c, libc/stdio/tmpfile.c libc/stdio/tmpnam.c libc/stdio/ungetc.c, libc/stdio/vasprintf.c libc/stdio/vfieeefp.h, libc/stdio/vfprintf.c libc/stdio/vfscanf.c, libc/stdio/vprintf.c libc/stdio/vscanf.c, libc/stdio/vsnprintf.c libc/stdio/vsprintf.c, libc/stdio/vsscanf.c libc/stdio/wbuf.c, libc/stdio/wsetup.c: Perform minor formatting changes. Move copyright notices to top of file, ensure that <_ansi.h> is included, be consistent with open parentheses, use _DEFUN macro, include "local.h" where needed, and remove various compiler warnings.
2004-04-24 04:01:55 +08:00
register FILE *fp)
2000-02-18 03:39:52 +08:00
{
register int i;
register unsigned char *p;
if (fp->_ub._base == fp->_ubuf)
{
/*
* Get a new buffer (rather than expanding the old one).
*/
if ((p = (unsigned char *) _malloc_r (rptr, (size_t) BUFSIZ)) == NULL)
2000-02-18 03:39:52 +08:00
return EOF;
fp->_ub._base = p;
fp->_ub._size = BUFSIZ;
p += BUFSIZ - sizeof (fp->_ubuf);
for (i = sizeof (fp->_ubuf); --i >= 0;)
p[i] = fp->_ubuf[i];
fp->_p = p;
return 0;
}
i = fp->_ub._size;
p = (unsigned char *) _realloc_r (rptr, (_PTR) (fp->_ub._base), i << 1);
2000-02-18 03:39:52 +08:00
if (p == NULL)
return EOF;
2004-04-23 Artem B. Bityuckiy <abitytsky@softminecorp.com> * libc/stdio/asprintf.c libc/stdio/clearerr.c, libc/stdio/fclose.c libc/stdio/fcloseall.c libc/stdio/fdopen.c, libc/stdio/feof.c libc/stdio/ferror.c libc/stdio/fflush.c, libc/stdio/fgetc.c libc/stdio/fgetpos.c libc/stdio/fgets.c, libc/stdio/fileno.c libc/stdio/findfp.c libc/stdio/fiprintf.c, libc/stdio/flags.c libc/stdio/fopen.c libc/stdio/fprintf.c, libc/stdio/fputc.c libc/stdio/fputs.c libc/stdio/fread.c, libc/stdio/freopen.c libc/stdio/fscanf.c libc/stdio/fseek.c, libc/stdio/fseeko.c libc/stdio/fsetpos.c libc/stdio/ftell.c, libc/stdio/ftello.c libc/stdio/fvwrite.c libc/stdio/fwalk.c, libc/stdio/fwrite.c libc/stdio/getc.c libc/stdio/getc_u.c, libc/stdio/getchar.c libc/stdio/getchar_u.c, libc/stdio/getdelim.c libc/stdio/getline.c libc/stdio/gets.c, libc/stdio/getw.c libc/stdio/iprintf.c libc/stdio/local.h, libc/stdio/makebuf.c libc/stdio/mktemp.c libc/stdio/perror.c, libc/stdio/printf.c libc/stdio/putc.c libc/stdio/putc_u.c, libc/stdio/putchar.c libc/stdio/putchar_u.c libc/stdio/puts.c, libc/stdio/putw.c libc/stdio/refill.c libc/stdio/remove.c, libc/stdio/rename.c libc/stdio/rewind.c libc/stdio/rget.c, libc/stdio/scanf.c libc/stdio/setbuf.c libc/stdio/setbuffer.c, libc/stdio/setlinebuf.c libc/stdio/setvbuf.c, libc/stdio/siprintf.c libc/stdio/snprintf.c, libc/stdio/sprintf.c libc/stdio/sscanf.c libc/stdio/stdio.c, libc/stdio/tmpfile.c libc/stdio/tmpnam.c libc/stdio/ungetc.c, libc/stdio/vasprintf.c libc/stdio/vfieeefp.h, libc/stdio/vfprintf.c libc/stdio/vfscanf.c, libc/stdio/vprintf.c libc/stdio/vscanf.c, libc/stdio/vsnprintf.c libc/stdio/vsprintf.c, libc/stdio/vsscanf.c libc/stdio/wbuf.c, libc/stdio/wsetup.c: Perform minor formatting changes. Move copyright notices to top of file, ensure that <_ansi.h> is included, be consistent with open parentheses, use _DEFUN macro, include "local.h" where needed, and remove various compiler warnings.
2004-04-24 04:01:55 +08:00
_CAST_VOID memcpy ((_PTR) (p + i), (_PTR) p, (size_t) i);
2000-02-18 03:39:52 +08:00
fp->_p = p + i;
fp->_ub._base = p;
fp->_ub._size = i << 1;
return 0;
}
int
_DEFUN(_ungetc_r, (rptr, c, fp),
struct _reent *rptr _AND
int c _AND
2004-04-23 Artem B. Bityuckiy <abitytsky@softminecorp.com> * libc/stdio/asprintf.c libc/stdio/clearerr.c, libc/stdio/fclose.c libc/stdio/fcloseall.c libc/stdio/fdopen.c, libc/stdio/feof.c libc/stdio/ferror.c libc/stdio/fflush.c, libc/stdio/fgetc.c libc/stdio/fgetpos.c libc/stdio/fgets.c, libc/stdio/fileno.c libc/stdio/findfp.c libc/stdio/fiprintf.c, libc/stdio/flags.c libc/stdio/fopen.c libc/stdio/fprintf.c, libc/stdio/fputc.c libc/stdio/fputs.c libc/stdio/fread.c, libc/stdio/freopen.c libc/stdio/fscanf.c libc/stdio/fseek.c, libc/stdio/fseeko.c libc/stdio/fsetpos.c libc/stdio/ftell.c, libc/stdio/ftello.c libc/stdio/fvwrite.c libc/stdio/fwalk.c, libc/stdio/fwrite.c libc/stdio/getc.c libc/stdio/getc_u.c, libc/stdio/getchar.c libc/stdio/getchar_u.c, libc/stdio/getdelim.c libc/stdio/getline.c libc/stdio/gets.c, libc/stdio/getw.c libc/stdio/iprintf.c libc/stdio/local.h, libc/stdio/makebuf.c libc/stdio/mktemp.c libc/stdio/perror.c, libc/stdio/printf.c libc/stdio/putc.c libc/stdio/putc_u.c, libc/stdio/putchar.c libc/stdio/putchar_u.c libc/stdio/puts.c, libc/stdio/putw.c libc/stdio/refill.c libc/stdio/remove.c, libc/stdio/rename.c libc/stdio/rewind.c libc/stdio/rget.c, libc/stdio/scanf.c libc/stdio/setbuf.c libc/stdio/setbuffer.c, libc/stdio/setlinebuf.c libc/stdio/setvbuf.c, libc/stdio/siprintf.c libc/stdio/snprintf.c, libc/stdio/sprintf.c libc/stdio/sscanf.c libc/stdio/stdio.c, libc/stdio/tmpfile.c libc/stdio/tmpnam.c libc/stdio/ungetc.c, libc/stdio/vasprintf.c libc/stdio/vfieeefp.h, libc/stdio/vfprintf.c libc/stdio/vfscanf.c, libc/stdio/vprintf.c libc/stdio/vscanf.c, libc/stdio/vsnprintf.c libc/stdio/vsprintf.c, libc/stdio/vsscanf.c libc/stdio/wbuf.c, libc/stdio/wsetup.c: Perform minor formatting changes. Move copyright notices to top of file, ensure that <_ansi.h> is included, be consistent with open parentheses, use _DEFUN macro, include "local.h" where needed, and remove various compiler warnings.
2004-04-24 04:01:55 +08:00
register FILE *fp)
2000-02-18 03:39:52 +08:00
{
if (c == EOF)
return (EOF);
/* Ensure stdio has been initialized.
??? Might be able to remove this as some other stdio routine should
have already been called to get the char we are un-getting. */
2006-09-27 05:22:19 +08:00
CHECK_INIT (rptr, fp);
2000-02-18 03:39:52 +08:00
_newlib_flockfile_start (fp);
2008-12-10 Corinna Vinschen <corinna@vinschen.de> Implement basic wide char stdio functionality, based on FreeBSD. * libc/include/stdio.h (__SORD): Define. (__SWID): Define. * libc/include/wchar.h: Add declarations for new wide char functions. (getwc): Define as macro. (getwchar): Ditto. (putwc): Ditto. (putwchar): Ditto. * libc/include/sys/reent.h (struct __sFILE): Add _mbstate member. (struct __sFILE64): Ditto. * libc/stdio/Makefile.am (ELIX_4_SOURCES): Add fgetwc.c, fgetws.c, fputwc.c, fputws.c, fwide.c, getwc.c, getwchar.c, putwc.c, putwchar.c and ungetwc.c. (CHEWOUT_FILES): Add fgetwc.def, fgetws.def, fputwc.def, fputws.def, fwide.def, getwc.def, getwchar.def, putwc.def, putwchar.def and ungetwc.def. Add header dependency rules for the new files. * libc/stdio/Makefile.in: Regenerate. * libc/stdio/fgetwc.c: New file, implementing fgetwc and _fgetwc_r. * libc/stdio/fgetws.c: New file, implementing fgetws and _fgetws_r. * libc/stdio/findfp.c (std): Initialize FILE's _mbstate member. (__sfmoreglue): Ditto. * libc/stdio/fputs.c (_fputs_r): Set stream orientation. * libc/stdio/fputwc.c: New file, implementing fputwc and _fputwc_r. * libc/stdio/fputws.c: New file, implementing fputws and _fputws_r. * libc/stdio/fread.c (_fread_r): Set stream orientation. * libc/stdio/freopen.c (_freopen_r): Reset stream orientation. Reset _mbstate. * libc/stdio/fseek.c (_fseek_r): Reset _mbstate. * libc/stdio/fwide.c: New file, implementing fwide and _fwide_r. * libc/stdio/fwrite.c (_fwrite_r): Set stream orientation. * libc/stdio/getwc.c: New file, implementing getwc and _getwc_r. * libc/stdio/getwchar.c: New file, implementing getwchar and _getwchar_r. * libc/stdio/local.h (ORIENT): New macro. * libc/stdio/puts.c (_puts_r): Set stream orientation. * libc/stdio/putwc.c: New file, implementing putwc and _putwc_r. * libc/stdio/putwchar.c: New file, implementing putwchar and _putwchar_r. * libc/stdio/refill.c (__srefill_r): Set stream orientation. * libc/stdio/stdio.tex: Add documentation for new functions. * libc/stdio/ungetc.c (_ungetc_r): Set stream orientation. * libc/stdio/ungetwc.c: New file, implementing ungetwc and _ungetwc_r. * libc/stdio/vfscanf.c (__SVFSCANF_R): Set stream orientation. * libc/stdio/wbuf.c (__swbuf_r): Ditto.
2008-12-11 07:43:12 +08:00
ORIENT (fp, -1);
2000-02-18 03:39:52 +08:00
/* After ungetc, we won't be at eof anymore */
fp->_flags &= ~__SEOF;
if ((fp->_flags & __SRD) == 0)
{
/*
* Not already reading: no good unless reading-and-writing.
* Otherwise, flush any current write stuff.
*/
if ((fp->_flags & __SRW) == 0)
{
_newlib_flockfile_exit (fp);
return EOF;
}
2000-02-18 03:39:52 +08:00
if (fp->_flags & __SWR)
{
if (_fflush_r (rptr, fp))
{
_newlib_flockfile_exit (fp);
return EOF;
}
2000-02-18 03:39:52 +08:00
fp->_flags &= ~__SWR;
fp->_w = 0;
fp->_lbfsize = 0;
}
fp->_flags |= __SRD;
}
c = (unsigned char) c;
/*
* If we are in the middle of ungetc'ing, just continue.
* This may require expanding the current ungetc buffer.
*/
if (HASUB (fp))
{
if (fp->_r >= fp->_ub._size && __submore (rptr, fp))
{
_newlib_flockfile_exit (fp);
return EOF;
}
2000-02-18 03:39:52 +08:00
*--fp->_p = c;
fp->_r++;
_newlib_flockfile_exit (fp);
2000-02-18 03:39:52 +08:00
return c;
}
/*
* If we can handle this by simply backing up, do so,
* but never replace the original character.
* (This makes sscanf() work when scanning `const' data.)
*/
if (fp->_bf._base != NULL && fp->_p > fp->_bf._base && fp->_p[-1] == c)
{
fp->_p--;
fp->_r++;
_newlib_flockfile_exit (fp);
2000-02-18 03:39:52 +08:00
return c;
}
/*
* Create an ungetc buffer.
* Initially, we will use the `reserve' buffer.
*/
fp->_ur = fp->_r;
fp->_up = fp->_p;
fp->_ub._base = fp->_ubuf;
fp->_ub._size = sizeof (fp->_ubuf);
fp->_ubuf[sizeof (fp->_ubuf) - 1] = c;
fp->_p = &fp->_ubuf[sizeof (fp->_ubuf) - 1];
fp->_r = 1;
_newlib_flockfile_end (fp);
2000-02-18 03:39:52 +08:00
return c;
}
#ifndef _REENT_ONLY
int
_DEFUN(ungetc, (c, fp),
int c _AND
register FILE *fp)
{
return _ungetc_r (_REENT, c, fp);
}
#endif /* !_REENT_ONLY */