27 lines
541 B
C
27 lines
541 B
C
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/*
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* ungetc.c - push a character back onto an input stream
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*/
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/* $Header$ */
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#include <stdio.h>
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#include "loc_incl.h"
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int
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ungetc(int ch, FILE *stream)
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{
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unsigned char *p;
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if (ch == EOF || !io_testflag(stream,_IOREADING))
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return EOF;
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if (stream->_ptr == stream->_buf) {
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if (stream->_count != 0) return EOF;
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stream->_ptr++;
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}
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stream->_count++;
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p = --(stream->_ptr); /* ??? Bloody vax assembler !!! */
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/* ungetc() in sscanf() shouldn't write in rom */
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if (*p != (unsigned char) ch)
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*p = (unsigned char) ch;
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return ch;
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}
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