1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* 23*0Sstevel@tonic-gate * Copyright 1990 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #include <fcntl.h> 30*0Sstevel@tonic-gate #include <unistd.h> 31*0Sstevel@tonic-gate #include <syscall.h> 32*0Sstevel@tonic-gate #include <sys/errno.h> 33*0Sstevel@tonic-gate 34*0Sstevel@tonic-gate #define OPEN_MAX 20 /* Taken from SVR4 limits.h */ 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate int dup2(fildes, fildes2) 37*0Sstevel@tonic-gate int fildes, /* file descriptor to be duplicated */ 38*0Sstevel@tonic-gate fildes2; /* desired file descriptor */ 39*0Sstevel@tonic-gate { 40*0Sstevel@tonic-gate int tmperrno; /* local work area */ 41*0Sstevel@tonic-gate register int open_max; /* max open files */ 42*0Sstevel@tonic-gate extern int errno; /* system error indicator */ 43*0Sstevel@tonic-gate int ret; /* return value */ 44*0Sstevel@tonic-gate int fds; /* duplicate files descriptor */ 45*0Sstevel@tonic-gate 46*0Sstevel@tonic-gate if ((open_max = ulimit(4, 0)) < 0) 47*0Sstevel@tonic-gate open_max = OPEN_MAX; /* take a guess */ 48*0Sstevel@tonic-gate 49*0Sstevel@tonic-gate /* Be sure fildes is valid and open */ 50*0Sstevel@tonic-gate if (fcntl(fildes, F_GETFL, 0) == -1) { 51*0Sstevel@tonic-gate errno = EBADF; 52*0Sstevel@tonic-gate return (-1); 53*0Sstevel@tonic-gate } 54*0Sstevel@tonic-gate 55*0Sstevel@tonic-gate /* Be sure fildes2 is in valid range */ 56*0Sstevel@tonic-gate if (fildes2 < 0 || fildes2 >= open_max) { 57*0Sstevel@tonic-gate errno = EBADF; 58*0Sstevel@tonic-gate return (-1); 59*0Sstevel@tonic-gate } 60*0Sstevel@tonic-gate 61*0Sstevel@tonic-gate /* Check if file descriptors are equal */ 62*0Sstevel@tonic-gate if (fildes == fildes2) { 63*0Sstevel@tonic-gate /* open and equal so no dup necessary */ 64*0Sstevel@tonic-gate return (fildes2); 65*0Sstevel@tonic-gate } 66*0Sstevel@tonic-gate /* Close in case it was open for another file */ 67*0Sstevel@tonic-gate /* Must save and restore errno in case file was not open */ 68*0Sstevel@tonic-gate tmperrno = errno; 69*0Sstevel@tonic-gate close(fildes2); 70*0Sstevel@tonic-gate errno = tmperrno; 71*0Sstevel@tonic-gate 72*0Sstevel@tonic-gate /* Do the dup */ 73*0Sstevel@tonic-gate if ((ret = fcntl(fildes, F_DUPFD, fildes2)) != -1) { 74*0Sstevel@tonic-gate if ((fds = fd_get(fildes)) != -1) 75*0Sstevel@tonic-gate fd_add(fildes2, fds); 76*0Sstevel@tonic-gate } 77*0Sstevel@tonic-gate return(ret); 78*0Sstevel@tonic-gate 79*0Sstevel@tonic-gate } 80