1 /* 2 * pANS stdio -- _IO_getc 3 */ 4 #include "iolib.h" 5 int _IO_getc(FILE *f){ 6 int cnt, n; 7 switch(f->state){ 8 default: /* CLOSED, WR, ERR, EOF */ 9 return EOF; 10 case OPEN: 11 _IO_setvbuf(f); 12 case RDWR: 13 case RD: 14 if(f->flags&STRING) return EOF; 15 if(f->buf == f->unbuf) 16 n = 1; 17 else 18 n = f->bufl; 19 cnt=read(f->fd, f->buf, n); 20 switch(cnt){ 21 case -1: f->state=ERR; return EOF; 22 case 0: f->state=END; return EOF; 23 default: 24 f->state=RD; 25 f->rp=f->buf; 26 f->wp=f->buf+cnt; 27 return (*f->rp++)&_IO_CHMASK; 28 } 29 } 30 } 31