1 /* 2 * Copyright (c) 1980 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 */ 6 7 #if defined(LIBC_SCCS) && !defined(lint) 8 static char sccsid[] = "@(#)filbuf.c 5.3 (Berkeley) 03/09/86"; 9 #endif LIBC_SCCS and not lint 10 11 #include <stdio.h> 12 #include <sys/types.h> 13 #include <sys/stat.h> 14 char *malloc(); 15 16 _filbuf(iop) 17 register FILE *iop; 18 { 19 int size; 20 struct stat stbuf; 21 extern char *_smallbuf; 22 char c; 23 24 if (iop->_flag & _IORW) 25 iop->_flag |= _IOREAD; 26 27 if ((iop->_flag&_IOREAD) == 0) 28 return(EOF); 29 if (iop->_flag&(_IOSTRG|_IOEOF)) 30 return(EOF); 31 tryagain: 32 if (iop->_base==NULL) { 33 if (iop->_flag&_IONBF) { 34 iop->_base = _smallbuf ? &_smallbuf[fileno(iop)] : &c; 35 goto tryagain; 36 } 37 if (fstat(fileno(iop), &stbuf) < 0 || stbuf.st_blksize <= NULL) 38 size = BUFSIZ; 39 else 40 size = stbuf.st_blksize; 41 if ((iop->_base = malloc(size)) == NULL) { 42 iop->_flag |= _IONBF; 43 goto tryagain; 44 } 45 iop->_flag |= _IOMYBUF; 46 iop->_bufsiz = size; 47 } 48 if (iop == stdin) { 49 if (stdout->_flag&_IOLBF) 50 fflush(stdout); 51 if (stderr->_flag&_IOLBF) 52 fflush(stderr); 53 } 54 iop->_cnt = read(fileno(iop), iop->_base, 55 iop->_flag & _IONBF ? 1 : iop->_bufsiz); 56 iop->_ptr = iop->_base; 57 if (iop->_flag & _IONBF && iop->_base == &c) 58 iop->_base = NULL; 59 if (--iop->_cnt < 0) { 60 if (iop->_cnt == -1) { 61 iop->_flag |= _IOEOF; 62 if (iop->_flag & _IORW) 63 iop->_flag &= ~_IOREAD; 64 } else 65 iop->_flag |= _IOERR; 66 iop->_cnt = 0; 67 return(EOF); 68 } 69 return(*iop->_ptr++&0377); 70 } 71