.\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)psignal.3 8.2 (Berkeley) 2/27/95 .\" $FreeBSD: src/lib/libc/gen/psignal.3,v 1.17 2007/01/09 00:27:54 imp Exp $ .\" .Dd February 27, 1995 .Dt PSIGNAL 3 .Os .Sh NAME .Nm psignal , .Nm strsignal , .Nm sys_siglist , .Nm sys_signame .Nd system signal messages .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In signal.h .Ft void .Fn psignal "unsigned sig" "const char *s" .Vt extern const char * const sys_siglist[] ; .Vt extern const char * const sys_signame[] ; .In string.h .Ft "char *" .Fn strsignal "int sig" .Sh DESCRIPTION The .Fn psignal and .Fn strsignal functions locate the descriptive message string for a signal number. .Pp The .Fn strsignal function accepts a signal number argument .Fa sig and returns a pointer to the corresponding message string. .Pp The .Fn psignal function accepts a signal number argument .Fa sig and writes it to the standard error. If the argument .Fa s is .Pf non- Dv NULL and does not point to the null character, .Fa s is written to the standard error file descriptor prior to the message string, immediately followed by a colon and a space. If the signal number is not recognized .Pq Xr sigaction 2 , the string .Dq "Unknown signal is produced. .Pp The message strings can be accessed directly through the external array .Va sys_siglist , indexed by recognized signal numbers. The external array .Va sys_signame is used similarly and contains short, lower-case abbreviations for signals which are useful for recognizing signal names in user input. The defined variable .Dv NSIG contains a count of the strings in .Va sys_siglist and .Va sys_signame . .Sh RETURN VALUES .Fn strsignal a pointer to the desired message or a NULL value indicating an error. This string is not to be freed by the caller. Beginning with Mac OSX 10.7, this string is unique to each thread. .Sh ERRORS .Fn strsignal will fail and no additional memory will be allocated if one of the following are true: .Bl -tag -width Er .It Bq Er ENOMEM There was insufficient memory to allocate storage space for the return value in the running thread. .El .Sh SEE ALSO .Xr sigaction 2 , .Xr perror 3 , .Xr strerror 3 .Sh HISTORY The .Fn psignal function appeared in .Bx 4.2 .