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