1 /* $NetBSD: eprintf.c,v 1.3 2025/11/19 09:43:27 nia Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Waldi Ravens. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <fcntl.h> 31 #include <errno.h> 32 #include <stdio.h> 33 #include <stdarg.h> 34 #include <unistd.h> 35 #include "libtos.h" 36 37 static int output_redirected = 0; 38 39 void 40 redirect_output(char *fn) 41 { 42 int fd; 43 44 fd = creat(fn, 0666); 45 if (fd < 0 || dup2(fd, STDOUT_FILENO) < 0) 46 fatal(errno, "%s", fn); 47 output_redirected = 1; 48 } 49 50 /* 51 * Print output to stderr. When output is redirected, 52 * also write it to stdout. 53 */ 54 int 55 eprintf(char *frm) 56 { 57 va_list args; 58 int rv; 59 60 va_start(args, frm); 61 rv = veprintf(frm, args); 62 va_end(args); 63 return(rv); 64 } 65 66 int 67 veprintf(char *frm, va_list args) 68 { 69 int rv; 70 71 rv = vfprintf(stderr, frm, args); 72 if (output_redirected) 73 vfprintf(stdout, frm, args); 74 return(rv); 75 } 76