1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)err.3 8.1 (Berkeley) 6/9/93 33.\" $Id: err.3,v 1.4 1993/11/25 02:48:54 jtc Exp $ 34.\" 35.Dd "June 9, 1993" 36.Dt ERR 3 37.Os BSD 4 38.Sh NAME 39.Nm err , 40.Nm verr , 41.Nm errx , 42.Nm verrx , 43.Nm warn , 44.Nm vwarn , 45.Nm warnx , 46.Nm vwarnx 47.Nd formatted error messages 48.Sh SYNOPSIS 49.Fd #include <err.h> 50.Ft void 51.Fn err "int eval" "const char *fmt" "..." 52.Ft void 53.Fn verr "int eval" "const char *fmt" "va_list args" 54.Ft void 55.Fn errx "int eval" "const char *fmt" "..." 56.Ft void 57.Fn verrx "int eval" "const char *fmt" "va_list args" 58.Ft void 59.Fn warn "const char *fmt" "..." 60.Ft void 61.Fn vwarn "const char *fmt" "va_list args" 62.Ft void 63.Fn warnx "const char *fmt" "..." 64.Ft void 65.Fn vwarnx "const char *fmt" "va_list args" 66.Sh DESCRIPTION 67The 68.Fn err 69and 70.Fn warn 71family of functions display a formatted error message on the standard 72error output. 73In all cases, the last component of the program name, a colon character, 74and a space are output. 75If the 76.Va fmt 77argument is not NULL, the formatted error message, a colon character, 78and a space are output. 79In the case of the 80.Fn err , 81.Fn verr , 82.Fn warn , 83and 84.Fn vwarn 85functions, the error message string affiliated with the current value of 86the global variable 87.Va errno 88is output. 89In all cases, the output is followed by a newline character. 90.Pp 91The 92.Fn err , 93.Fn verr , 94.Fn errx , 95and 96.Fn verrx 97functions do not return, but exit with the value of the argument 98.Fa eval . 99.Sh EXAMPLES 100Display the current errno information string and exit: 101.Bd -literal -offset indent 102if ((p = malloc(size)) == NULL) 103 err(1, NULL); 104if ((fd = open(file_name, O_RDONLY, 0)) == -1) 105 err(1, "%s", file_name); 106.Ed 107.Pp 108Display an error message and exit: 109.Bd -literal -offset indent 110if (tm.tm_hour < START_TIME) 111 errx(1, "too early, wait until %s", start_time_string); 112.Ed 113.Pp 114Warn of an error: 115.Bd -literal -offset indent 116if ((fd = open(raw_device, O_RDONLY, 0)) == -1) 117 warnx("%s: %s: trying the block device", 118 raw_device, strerror(errno)); 119if ((fd = open(block_device, O_RDONLY, 0)) == -1) 120 err(1, "%s", block_device); 121.Ed 122.Sh SEE ALSO 123.Xr strerror 3 124.Sh HISTORY 125The 126.Fn err 127and 128.Fn warn 129functions first appeared in 130.Bx 4.4 . 131