'\" t
.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.\" References consulted:
.\"     Linux libc source code
.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\"     386BSD man pages
.\" Modified Sat Jul 24 18:45:17 1993 by Rik Faith (faith@cs.unc.edu)
.TH psignal 3 2023-10-31 "Linux man-pages 6.7"
.SH NAME
psignal, psiginfo \- print signal description
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <signal.h>
.P
.BI "void psignal(int " sig ", const char *" s );
.BI "void psiginfo(const siginfo_t *" pinfo ", const char *" s );
.fi
.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.P
.BR psignal ():
.nf
    Since glibc 2.19:
            _DEFAULT_SOURCE
    glibc 2.19 and earlier:
        _BSD_SOURCE || _SVID_SOURCE
.fi
.P
.BR psiginfo ():
.nf
    _POSIX_C_SOURCE >= 200809L
.fi
.SH DESCRIPTION
The
.BR psignal ()
function displays a message on \fIstderr\fP
consisting of the string \fIs\fP, a colon, a space, a string
describing the signal number \fIsig\fP, and a trailing newline.
If the string \fIs\fP is NULL or empty, the colon and space are omitted.
If \fIsig\fP is invalid,
the message displayed will indicate an unknown signal.
.P
The
.BR psiginfo ()
function is like
.BR psignal (),
except that it displays information about the signal described by
.IR pinfo ,
which should point to a valid
.I siginfo_t
structure.
As well as the signal description,
.BR psiginfo ()
displays information about the origin of the signal,
and other information relevant to the signal
(e.g., the relevant memory address for hardware-generated signals,
the child process ID for
.BR SIGCHLD ,
and the user ID and process ID of the sender, for signals set using
.BR kill (2)
or
.BR sigqueue (3)).
.SH RETURN VALUE
The
.BR psignal ()
and
.BR psiginfo ()
functions return no value.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR psignal (),
.BR psiginfo ()
T}	Thread safety	MT-Safe locale
.TE
.SH STANDARDS
POSIX.1-2008.
.SH HISTORY
glibc 2.10.
POSIX.1-2008, 4.3BSD.
.SH BUGS
Up to glibc 2.12,
.BR psiginfo ()
had the following bugs:
.IP \[bu] 3
In some circumstances, a trailing newline is not printed.
.\" FIXME . http://sourceware.org/bugzilla/show_bug.cgi?id=12107
.\" Reportedly now fixed; check glibc 2.13
.IP \[bu]
Additional details are not displayed for real-time signals.
.\" FIXME . http://sourceware.org/bugzilla/show_bug.cgi?id=12108
.\" Reportedly now fixed; check glibc 2.13
.SH SEE ALSO
.BR sigaction (2),
.BR perror (3),
.BR strsignal (3),
.BR signal (7)