1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 1986 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 3.11 */ 31 32 /*LINTLIBRARY*/ 33 /* 34 * This version reads directly from the buffer rather than looping on getc. 35 * Ptr args aren't checked for NULL because the program would be a 36 * catastrophic mess anyway. Better to abort than just to return NULL. 37 */ 38 #include <stdio.h> 39 #include "stdiom.h" 40 41 #define MIN(x, y) (x < y ? x : y) 42 43 extern int _filbuf(); 44 extern _bufsync(); 45 extern char *memcpy(); 46 47 int 48 fread(ptr, size, count, iop) 49 char *ptr; 50 int size, count; 51 register FILE *iop; 52 { 53 register unsigned int nleft; 54 register int n; 55 56 if (size <= 0 || count <= 0) return 0; 57 nleft = count * size; 58 59 /* Put characters in the buffer */ 60 /* note that the meaning of n when just starting this loop is 61 irrelevant. It is defined in the loop */ 62 for ( ; ; ) { 63 if (iop->_cnt <= 0) { /* empty buffer */ 64 if (_filbuf(iop) == EOF) 65 return (count - (nleft + size - 1)/size); 66 iop->_ptr--; 67 iop->_cnt++; 68 } 69 n = MIN(nleft, iop->_cnt); 70 ptr = memcpy(ptr, (char *) iop->_ptr, n) + n; 71 iop->_cnt -= n; 72 iop->_ptr += n; 73 _BUFSYNC(iop); 74 if ((nleft -= n) == 0) 75 return (count); 76 } 77 } 78