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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1988 AT&T */ 28 /* All Rights Reserved */ 29 30 #include "lint.h" 31 #include "file64.h" 32 #include "mtlib.h" 33 #include <sys/types.h> 34 #include <stdio.h> 35 #include <thread.h> 36 #include <synch.h> 37 #include "stdiom.h" 38 39 int _ungetc_unlocked(int c, FILE *iop); 40 41 int 42 ungetc(int c, FILE *iop) 43 { 44 FLOCKRETURN(iop, _ungetc_unlocked(c, iop)) 45 } 46 47 /* 48 * Called internally by the library (instead of the safe "ungetc") when 49 * iop->_lock is already held at a higher level - required since we do not 50 * have recursive locks. 51 */ 52 int 53 _ungetc_unlocked(int c, FILE *iop) 54 { 55 if (c == EOF) 56 return (EOF); 57 if (iop->_ptr <= iop->_base) { 58 if (iop->_base == 0) { 59 if (_findbuf(iop) == 0) 60 return (EOF); 61 } else if (iop->_ptr <= iop->_base - PUSHBACK) 62 return (EOF); 63 } 64 if ((iop->_flag & _IOREAD) == 0) /* basically a no-op on write stream */ 65 ++iop->_ptr; 66 if (*--iop->_ptr != (unsigned char) c) 67 *iop->_ptr = (unsigned char) c; /* was *--iop->_ptr = c; */ 68 ++iop->_cnt; 69 iop->_flag &= ~_IOEOF; 70 return (c); 71 } 72