17c478bd9Sstevel@tonic-gate /* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*d4188195Sraf * Common Development and Distribution License (the "License"). 6*d4188195Sraf * You may not use this file except in compliance with the License. 77c478bd9Sstevel@tonic-gate * 87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 117c478bd9Sstevel@tonic-gate * and limitations under the License. 127c478bd9Sstevel@tonic-gate * 137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 187c478bd9Sstevel@tonic-gate * 197c478bd9Sstevel@tonic-gate * CDDL HEADER END 207c478bd9Sstevel@tonic-gate */ 21*d4188195Sraf 227c478bd9Sstevel@tonic-gate /* 23*d4188195Sraf * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 247c478bd9Sstevel@tonic-gate * Use is subject to license terms. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 277c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 287c478bd9Sstevel@tonic-gate 297c478bd9Sstevel@tonic-gate #include <fcntl.h> 307c478bd9Sstevel@tonic-gate #include <unistd.h> 31*d4188195Sraf #include <sys/syscall.h> 32*d4188195Sraf #include <errno.h> 337c478bd9Sstevel@tonic-gate 347c478bd9Sstevel@tonic-gate #define OPEN_MAX 20 /* Taken from SVR4 limits.h */ 357c478bd9Sstevel@tonic-gate 36*d4188195Sraf int 37*d4188195Sraf dup2( 387c478bd9Sstevel@tonic-gate int fildes, /* file descriptor to be duplicated */ 39*d4188195Sraf int fildes2) /* desired file descriptor */ 407c478bd9Sstevel@tonic-gate { 417c478bd9Sstevel@tonic-gate int tmperrno; /* local work area */ 42*d4188195Sraf int open_max; /* max open files */ 437c478bd9Sstevel@tonic-gate int ret; /* return value */ 447c478bd9Sstevel@tonic-gate int fds; /* duplicate files descriptor */ 457c478bd9Sstevel@tonic-gate 467c478bd9Sstevel@tonic-gate if ((open_max = ulimit(4, 0)) < 0) 477c478bd9Sstevel@tonic-gate open_max = OPEN_MAX; /* take a guess */ 487c478bd9Sstevel@tonic-gate 497c478bd9Sstevel@tonic-gate /* Be sure fildes is valid and open */ 507c478bd9Sstevel@tonic-gate if (fcntl(fildes, F_GETFL, 0) == -1) { 517c478bd9Sstevel@tonic-gate errno = EBADF; 527c478bd9Sstevel@tonic-gate return (-1); 537c478bd9Sstevel@tonic-gate } 547c478bd9Sstevel@tonic-gate 557c478bd9Sstevel@tonic-gate /* Be sure fildes2 is in valid range */ 567c478bd9Sstevel@tonic-gate if (fildes2 < 0 || fildes2 >= open_max) { 577c478bd9Sstevel@tonic-gate errno = EBADF; 587c478bd9Sstevel@tonic-gate return (-1); 597c478bd9Sstevel@tonic-gate } 607c478bd9Sstevel@tonic-gate 617c478bd9Sstevel@tonic-gate /* Check if file descriptors are equal */ 627c478bd9Sstevel@tonic-gate if (fildes == fildes2) { 637c478bd9Sstevel@tonic-gate /* open and equal so no dup necessary */ 647c478bd9Sstevel@tonic-gate return (fildes2); 657c478bd9Sstevel@tonic-gate } 667c478bd9Sstevel@tonic-gate /* Close in case it was open for another file */ 677c478bd9Sstevel@tonic-gate /* Must save and restore errno in case file was not open */ 687c478bd9Sstevel@tonic-gate tmperrno = errno; 697c478bd9Sstevel@tonic-gate close(fildes2); 707c478bd9Sstevel@tonic-gate errno = tmperrno; 717c478bd9Sstevel@tonic-gate 727c478bd9Sstevel@tonic-gate /* Do the dup */ 737c478bd9Sstevel@tonic-gate if ((ret = fcntl(fildes, F_DUPFD, fildes2)) != -1) { 747c478bd9Sstevel@tonic-gate if ((fds = fd_get(fildes)) != -1) 757c478bd9Sstevel@tonic-gate fd_add(fildes2, fds); 767c478bd9Sstevel@tonic-gate } 777c478bd9Sstevel@tonic-gate return (ret); 787c478bd9Sstevel@tonic-gate } 79