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 1.3 */ 31 32 /*LINTLIBRARY*/ 33 /* 34 * Seek for standard library. Coordinates with buffering. 35 */ 36 #include <stdio.h> 37 38 extern long lseek(); 39 extern int fflush(); 40 41 int 42 fseek(iop, offset, ptrname) 43 register FILE *iop; 44 long offset; 45 int ptrname; 46 { 47 register int resync, c; 48 long p = -1; /* can't happen? */ 49 50 iop->_flag &= ~_IOEOF; 51 if(iop->_flag & _IOREAD) { 52 if(ptrname < 2 && iop->_base && !(iop->_flag&_IONBF)) { 53 c = iop->_cnt; 54 p = offset; 55 if(ptrname == 0) { 56 long curpos = lseek(fileno(iop), 0L, 1); 57 if (curpos == -1) 58 return (-1); 59 p += c - curpos; 60 resync = offset&01; 61 } else { 62 offset -= (long)c; 63 resync = 0; 64 } 65 if(!(iop->_flag&_IORW) && c > 0 && p <= c && 66 p >= iop->_base - iop->_ptr) { 67 iop->_ptr += (int)p; 68 iop->_cnt -= (int)p; 69 return(0); 70 } 71 } else 72 resync = 0; 73 if(iop->_flag & _IORW) { 74 iop->_ptr = iop->_base; 75 iop->_flag &= ~_IOREAD; 76 resync = 0; 77 } 78 p = lseek(fileno(iop), offset-resync, ptrname); 79 iop->_cnt = 0; 80 if (resync && p != -1) 81 if (getc(iop) == EOF) 82 p = -1; 83 } else if(iop->_flag & (_IOWRT | _IORW)) { 84 p = fflush(iop); 85 iop->_cnt = 0; 86 if(iop->_flag & _IORW) { 87 iop->_flag &= ~_IOWRT; 88 iop->_ptr = iop->_base; 89 } 90 return(lseek(fileno(iop), offset, ptrname) == -1 || p == EOF ? 91 -1 : 0); 92 } 93 return((p == -1)? -1: 0); 94 } 95