38 lines
855 B
C
38 lines
855 B
C
/*
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* This file is part of the UCB release of Plan 9. It is subject to the license
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* terms in the LICENSE file found in the top-level directory of this
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* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
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* part of the UCB release of Plan 9, including this file, may be copied,
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* modified, propagated, or distributed except according to the terms contained
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* in the LICENSE file.
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*/
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/*
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* pANS stdio -- ungetc
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*/
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#include "iolib.h"
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int ungetc(int c, FILE *f){
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if(c==EOF) return EOF;
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switch(f->state){
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default: /* WR */
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f->state=ERR;
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return EOF;
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case CLOSED:
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case ERR:
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return EOF;
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case OPEN:
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_IO_setvbuf(f);
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case RDWR:
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case END:
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f->rp=f->wp=f->buf+(f->bufl==0?1:f->bufl);
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f->state=RD;
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case RD:
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if(f->rp==f->buf) return EOF;
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if(f->flags&STRING)
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f->rp--;
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else
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*--f->rp=c;
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return (char)c;
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}
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}
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