1.\" Copyright (c) 1983, 1991, 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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd May 30, 2016 29.Dt PSIGNAL 3 30.Os 31.Sh NAME 32.Nm psignal , 33.Nm strsignal , 34.Nm sys_siglist , 35.Nm sys_signame 36.Nd system signal messages 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In signal.h 41.Ft void 42.Fn psignal "int sig" "const char *s" 43.Vt extern const char * const sys_siglist[] ; 44.Vt extern const char * const sys_signame[] ; 45.In string.h 46.Ft "char *" 47.Fn strsignal "int sig" 48.Sh DESCRIPTION 49The 50.Fn psignal 51and 52.Fn strsignal 53functions locate the descriptive message 54string for a signal number. 55.Pp 56The 57.Fn strsignal 58function accepts a signal number argument 59.Fa sig 60and returns a pointer to the corresponding message string. 61.Pp 62The 63.Fn psignal 64function accepts a signal number argument 65.Fa sig 66and writes it to the standard error. 67If the argument 68.Fa s 69is 70.Pf non- Dv NULL 71and does not point to the null character, 72.Fa s 73is written to the standard error file descriptor 74prior to the message string, 75immediately followed by a colon and a space. 76If the signal number is not recognized 77.Pq Xr sigaction 2 , 78the string 79.Dq "Unknown signal" 80is produced. 81.Pp 82The message strings can be accessed directly 83through the external array 84.Va sys_siglist , 85indexed by recognized signal numbers. 86The external array 87.Va sys_signame 88is used similarly and 89contains short, upper-case abbreviations for signals 90which are useful for recognizing signal names 91in user input. 92The defined variable 93.Dv NSIG 94contains a count of the strings in 95.Va sys_siglist 96and 97.Va sys_signame . 98.Sh SEE ALSO 99.Xr sigaction 2 , 100.Xr perror 3 , 101.Xr strerror 3 102.Sh HISTORY 103The 104.Fn psignal 105function appeared in 106.Bx 4.2 . 107