diff options
Diffstat (limited to 'newlib/libc/stdio/ungetc.c')
| -rw-r--r-- | newlib/libc/stdio/ungetc.c | 215 |
1 files changed, 0 insertions, 215 deletions
diff --git a/newlib/libc/stdio/ungetc.c b/newlib/libc/stdio/ungetc.c deleted file mode 100644 index d65cddab6..000000000 --- a/newlib/libc/stdio/ungetc.c +++ /dev/null @@ -1,215 +0,0 @@ -/* - * 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>>. -*/ - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "%W% (Berkeley) %G%"; -#endif /* LIBC_SCCS and not lint */ - -#include <_ansi.h> -#include <reent.h> -#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 - register FILE *fp) -{ - 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) - 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); - if (p == NULL) - return EOF; - _CAST_VOID memcpy ((_PTR) (p + i), (_PTR) p, (size_t) i); - 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 - register FILE *fp) -{ - 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. */ - - CHECK_INIT (rptr, fp); - - _flockfile (fp); - - /* 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) - { - _funlockfile (fp); - return EOF; - } - if (fp->_flags & __SWR) - { - if (_fflush_r (rptr, fp)) - { - _funlockfile (fp); - return EOF; - } - 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)) - { - _funlockfile (fp); - return EOF; - } - *--fp->_p = c; - fp->_r++; - _funlockfile (fp); - 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++; - _funlockfile (fp); - 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; - _funlockfile (fp); - 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 */ |