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- /*
- * 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->wp=f->buf;
- if(f->bufl==0)
- f->wp += 1;
- else
- f->wp += f->bufl;
- f->rp = f->wp;
- 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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