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.\" $FreeBSD: src/lib/libc/gen/psignal.3,v 1.10.2.5 2003/03/15 15:11:05 trhodes Exp $ 30.\" 31.Dd January 2, 2015 32.Dt PSIGNAL 3 33.Os 34.Sh NAME 35.Nm psignal , 36.Nm psiginfo , 37.Nm strsignal , 38.Nm sys_siglist , 39.Nm sys_signame , 40.Nm sys_nsig 41.Nd system signal messages 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In signal.h 46.Ft void 47.Fn psignal "unsigned sig" "const char *s" 48.Ft void 49.Fn psiginfo "const siginfo_t *si" "const char *s" 50.Vt extern const char * const sys_siglist[] ; 51.Vt extern const char * const sys_signame[] ; 52.Vt extern const int sys_nsig ; 53.In string.h 54.Ft "char *" 55.Fn strsignal "int sig" 56.Sh DESCRIPTION 57The 58.Fn psignal 59and 60.Fn strsignal 61functions locate the descriptive message 62string for a signal number. 63.Pp 64The 65.Fn strsignal 66function accepts a signal number argument 67.Fa sig 68and returns a pointer to the corresponding message string. 69.Pp 70The 71.Fn psignal 72function accepts a signal number argument 73.Fa sig 74and writes it to the standard error. 75If the argument 76.Fa s 77is 78.Pf non- Dv NULL 79and does not point to the null character, 80.Fa s 81is written to the standard error file descriptor 82prior to the message string, 83immediately followed by a colon and a space. 84If the signal number is not recognized 85.Pq Xr sigaction 2 , 86the string 87.Dq "Unknown signal" 88is produced. 89.Pp 90The 91.Fn psiginfo 92function is similar to 93.Fn psignal , 94except that the signal number information is taken from the 95.Fa si 96argument which is a 97.Vt siginfo_t 98structure. 99.Pp 100The message strings can be accessed directly 101through the external array 102.Va sys_siglist , 103indexed by recognized signal numbers. 104The external array 105.Va sys_signame 106is used similarly and 107contains short, lower-case abbreviations for signals 108which are useful for recognizing signal names 109in user input. 110The external variable 111.Va sys_nsig 112contains a count of the strings in 113.Va sys_siglist 114and 115.Va sys_signame . 116Note that the defined variable 117.Dv NSIG 118will typically be the same as 119.Va sys_nsig , 120but might be different due to newer or older kernels and newer or 121older libc libraries. For maximum portability you must use 122.Va sys_nsig 123to limit-check the above arrays. Additionally, you should check 124for 125.Dv NULL 126array entries and generate a generic signal name in those cases. 127.Sh SEE ALSO 128.Xr sigaction 2 , 129.Xr perror 3 , 130.Xr strerror 3 131.Sh HISTORY 132The 133.Fn psignal 134function appeared in 135.Bx 4.2 . 136The 137.Fn psiginfo 138function appeared in 139.Dx 4.1 . 140