27 lines
		
	
	
		
			541 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			27 lines
		
	
	
		
			541 B
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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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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| 
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| #include	<stdio.h>
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| #include	"loc_incl.h"
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| 
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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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| 
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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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