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 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* Copyright (c) 1988 AT&T */ 30 /* All Rights Reserved */ 31 32 33 #include "synonyms.h" 34 #include "file64.h" 35 #include "mtlib.h" 36 #include <sys/types.h> 37 #include <stdio.h> 38 #include <thread.h> 39 #include <synch.h> 40 #include "stdiom.h" 41 42 int _ungetc_unlocked(int c, FILE *iop); 43 44 int 45 ungetc(int c, FILE *iop) 46 { 47 FLOCKRETURN(iop, _ungetc_unlocked(c, iop)) 48 } 49 50 /* 51 * Called internally by the library (instead of the safe "ungetc") when 52 * iop->_lock is already held at a higher level - required since we do not 53 * have recursive locks. 54 */ 55 int 56 _ungetc_unlocked(int c, FILE *iop) 57 { 58 if (c == EOF) 59 return (EOF); 60 if (iop->_ptr <= iop->_base) { 61 if (iop->_base == 0) { 62 if (_findbuf(iop) == 0) 63 return (EOF); 64 } else if (iop->_ptr <= iop->_base - PUSHBACK) 65 return (EOF); 66 } 67 if ((iop->_flag & _IOREAD) == 0) /* basically a no-op on write stream */ 68 ++iop->_ptr; 69 if (*--iop->_ptr != (unsigned char) c) 70 *iop->_ptr = (unsigned char) c; /* was *--iop->_ptr = c; */ 71 ++iop->_cnt; 72 iop->_flag &= ~_IOEOF; 73 return (c); 74 } 75