1 /*- 2 * Copyright (c) 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #ifndef lint 31 #endif /* not lint */ 32 #include <sys/cdefs.h> 33 #include <sys/types.h> 34 #include <sys/stat.h> 35 36 #include <err.h> 37 #include <unistd.h> 38 39 #include "stty.h" 40 #include "extern.h" 41 42 /* 43 * Gross, but since we're changing the control descriptor from 1 to 0, most 44 * users will be probably be doing "stty > /dev/sometty" by accident. If 1 45 * and 2 are both ttys, but not the same, assume that 1 was incorrectly 46 * redirected. 47 */ 48 void 49 checkredirect(void) 50 { 51 struct stat sb1, sb2; 52 53 if (isatty(STDOUT_FILENO) && isatty(STDERR_FILENO) && 54 !fstat(STDOUT_FILENO, &sb1) && !fstat(STDERR_FILENO, &sb2) && 55 (sb1.st_rdev != sb2.st_rdev)) 56 warnx("stdout appears redirected, but stdin is the control descriptor"); 57 } 58