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.\" @(#)psignal.3 8.2 (Berkeley) 2/27/95 29.\" 30.Dd May 30, 2016 31.Dt PSIGNAL 3 32.Os 33.Sh NAME 34.Nm psignal , 35.Nm strsignal , 36.Nm sys_siglist , 37.Nm sys_signame 38.Nd system signal messages 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In signal.h 43.Ft void 44.Fn psignal "int sig" "const char *s" 45.Vt extern const char * const sys_siglist[] ; 46.Vt extern const char * const sys_signame[] ; 47.In string.h 48.Ft "char *" 49.Fn strsignal "int sig" 50.Sh DESCRIPTION 51The 52.Fn psignal 53and 54.Fn strsignal 55functions locate the descriptive message 56string for a signal number. 57.Pp 58The 59.Fn strsignal 60function accepts a signal number argument 61.Fa sig 62and returns a pointer to the corresponding message string. 63.Pp 64The 65.Fn psignal 66function accepts a signal number argument 67.Fa sig 68and writes it to the standard error. 69If the argument 70.Fa s 71is 72.Pf non- Dv NULL 73and does not point to the null character, 74.Fa s 75is written to the standard error file descriptor 76prior to the message string, 77immediately followed by a colon and a space. 78If the signal number is not recognized 79.Pq Xr sigaction 2 , 80the string 81.Dq "Unknown signal" 82is produced. 83.Pp 84The message strings can be accessed directly 85through the external array 86.Va sys_siglist , 87indexed by recognized signal numbers. 88The external array 89.Va sys_signame 90is used similarly and 91contains short, upper-case abbreviations for signals 92which are useful for recognizing signal names 93in user input. 94The defined variable 95.Dv NSIG 96contains a count of the strings in 97.Va sys_siglist 98and 99.Va sys_signame . 100.Sh SEE ALSO 101.Xr sigaction 2 , 102.Xr perror 3 , 103.Xr strerror 3 104.Sh HISTORY 105The 106.Fn psignal 107function appeared in 108.Bx 4.2 . 109