1.\" $NetBSD: err.3,v 1.8 1997/09/29 05:33:03 enami Exp $ 2.\" 3.\" Copyright (c) 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)err.3 8.1 (Berkeley) 6/9/93 35.\" 36.Dd June 9, 1993 37.Dt ERR 3 38.Os BSD 4 39.Sh NAME 40.Nm err , 41.Nm verr , 42.Nm errx , 43.Nm verrx , 44.Nm warn , 45.Nm vwarn , 46.Nm warnx , 47.Nm vwarnx 48.Nd formatted error messages 49.Sh SYNOPSIS 50.Fd #include <err.h> 51.Ft void 52.Fn err "int eval" "const char *fmt" "..." 53.Ft void 54.Fn verr "int eval" "const char *fmt" "va_list args" 55.Ft void 56.Fn errx "int eval" "const char *fmt" "..." 57.Ft void 58.Fn verrx "int eval" "const char *fmt" "va_list args" 59.Ft void 60.Fn warn "const char *fmt" "..." 61.Ft void 62.Fn vwarn "const char *fmt" "va_list args" 63.Ft void 64.Fn warnx "const char *fmt" "..." 65.Ft void 66.Fn vwarnx "const char *fmt" "va_list args" 67.Sh DESCRIPTION 68The 69.Fn err 70and 71.Fn warn 72family of functions display a formatted error message on the standard 73error output. 74In all cases, the last component of the program name, a colon character, 75and a space are output. 76If the 77.Fa fmt 78argument is not NULL, the formatted error message is 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 next, preceded by a colon character and a space if 89.Fa fmt 90is not NULL. 91In all cases, the output is followed by a newline character. 92.Pp 93The 94.Fn err , 95.Fn verr , 96.Fn errx , 97and 98.Fn verrx 99functions do not return, but exit with the value of the argument 100.Fa eval . 101.Sh EXAMPLES 102Display the current errno information string and exit: 103.Bd -literal -offset indent 104if ((p = malloc(size)) == NULL) 105 err(1, NULL); 106if ((fd = open(file_name, O_RDONLY, 0)) == -1) 107 err(1, "%s", file_name); 108.Ed 109.Pp 110Display an error message and exit: 111.Bd -literal -offset indent 112if (tm.tm_hour < START_TIME) 113 errx(1, "too early, wait until %s", start_time_string); 114.Ed 115.Pp 116Warn of an error: 117.Bd -literal -offset indent 118if ((fd = open(raw_device, O_RDONLY, 0)) == -1) 119 warnx("%s: %s: trying the block device", 120 raw_device, strerror(errno)); 121if ((fd = open(block_device, O_RDONLY, 0)) == -1) 122 warn("%s", block_device); 123.Ed 124.Sh SEE ALSO 125.Xr strerror 3 126.Sh HISTORY 127The 128.Fn err 129and 130.Fn warn 131functions first appeared in 132.Bx 4.4 . 133