10Sstevel@tonic-gate /* 20Sstevel@tonic-gate * CDDL HEADER START 30Sstevel@tonic-gate * 40Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*3224Sraf * Common Development and Distribution License (the "License"). 6*3224Sraf * You may not use this file except in compliance with the License. 70Sstevel@tonic-gate * 80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 100Sstevel@tonic-gate * See the License for the specific language governing permissions 110Sstevel@tonic-gate * and limitations under the License. 120Sstevel@tonic-gate * 130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 170Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 180Sstevel@tonic-gate * 190Sstevel@tonic-gate * CDDL HEADER END 200Sstevel@tonic-gate */ 21*3224Sraf 220Sstevel@tonic-gate /* 23*3224Sraf * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 240Sstevel@tonic-gate * Use is subject to license terms. 250Sstevel@tonic-gate */ 260Sstevel@tonic-gate 270Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 280Sstevel@tonic-gate 290Sstevel@tonic-gate #include <fcntl.h> 300Sstevel@tonic-gate #include <unistd.h> 31*3224Sraf #include <sys/syscall.h> 32*3224Sraf #include <errno.h> 33*3224Sraf 34*3224Sraf #define OPEN_MAX 20 /* Taken from SVR4 limits.h */ 350Sstevel@tonic-gate 36*3224Sraf int 37*3224Sraf dup2( 38*3224Sraf int fildes, /* file descriptor to be duplicated */ 39*3224Sraf int fildes2) /* desired file descriptor */ 400Sstevel@tonic-gate { 41*3224Sraf int tmperrno; /* local work area */ 42*3224Sraf int open_max; /* max open files */ 43*3224Sraf int ret; /* return value */ 44*3224Sraf int fds; /* duplicate files descriptor */ 450Sstevel@tonic-gate 46*3224Sraf if ((open_max = ulimit(4, 0)) < 0) 47*3224Sraf open_max = OPEN_MAX; /* take a guess */ 480Sstevel@tonic-gate 49*3224Sraf /* Be sure fildes is valid and open */ 50*3224Sraf if (fcntl(fildes, F_GETFL, 0) == -1) { 51*3224Sraf errno = EBADF; 52*3224Sraf return (-1); 53*3224Sraf } 540Sstevel@tonic-gate 55*3224Sraf /* Be sure fildes2 is in valid range */ 56*3224Sraf if (fildes2 < 0 || fildes2 >= open_max) { 57*3224Sraf errno = EBADF; 58*3224Sraf return (-1); 59*3224Sraf } 600Sstevel@tonic-gate 61*3224Sraf /* Check if file descriptors are equal */ 62*3224Sraf if (fildes == fildes2) { 63*3224Sraf /* open and equal so no dup necessary */ 64*3224Sraf return (fildes2); 65*3224Sraf } 66*3224Sraf /* Close in case it was open for another file */ 67*3224Sraf /* Must save and restore errno in case file was not open */ 68*3224Sraf tmperrno = errno; 69*3224Sraf close(fildes2); 70*3224Sraf errno = tmperrno; 710Sstevel@tonic-gate 72*3224Sraf /* Do the dup */ 73*3224Sraf if ((ret = fcntl(fildes, F_DUPFD, fildes2)) != -1) { 74*3224Sraf if ((fds = fd_get(fildes)) != -1) 75*3224Sraf fd_add(fildes2, fds); 76*3224Sraf } 77*3224Sraf return (ret); 780Sstevel@tonic-gate } 79