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.\"
.\" libexplain - Explain errno values returned by libc functions
.\" Copyright (C) 2011 Peter Miller
.\"
.\" This program is free software; you can redistribute it and/or modify it
.\" under the terms of the GNU General Public License as published by the
.\" Free Software Foundation; either version 3 of the License, or (at your
.\" option) any later version.
.\"
.\" This program is distributed in the hope that it will be useful, but
.\" WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
.\" General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public License along
.\" with this program. If not, see <http://www.gnu.org/licenses/>.
.\"
.ds n) explain_setpgrp_or_die
.cp 0 \" Solaris defaults to ''.cp 1'', sheesh.
.TH explain_setpgrp_or_die 3
.SH NAME
explain_setpgrp_or_die \- set process group and report errors
.if require_index \{
.XX "explain_setpgrp_or_die(3)" \
"set process group and report errors"
.\}
.SH SYNOPSIS
#include <libexplain/setpgrp.h>
.sp 0.3
void explain_setpgrp_or_die(pid_t pid, pid_t pgid);
.br
int explain_setpgrp_on_error(pid_t pid, pid_t pgid);
.SH DESCRIPTION
The \f[B]explain_setpgrp_or_die\fP function is used to call the
\f[I]setpgrp\fP(2) system call. On failure an explanation will be printed
to \f[I]stderr\fP, obtained from the \f[I]explain_setpgrp\fP(3) function,
and then the process terminates by calling \f[CW]exit(EXIT_FAILURE)\fP.
.PP
The \f[B]explain_setpgrp_on_error\fP function is used to call the
\f[I]setpgrp\fP(2) system call. On failure an explanation will be printed
to \f[I]stderr\fP, obtained from the \f[I]explain_setpgrp\fP(3) function,
but still returns to the caller.
.TP 8n
\f[I]pid\fP
The pid, exactly as to be passed to the \f[I]setpgrp\fP(2) system call.
.TP 8n
\f[I]pgid\fP
The pgid, exactly as to be passed to the \f[I]setpgrp\fP(2) system call.
.PP
\f[B]Note:\fP the \f[I]setpgrp\fP(2) function has two implementations.
The System V version has no arguments, while the BSD version has two
arguments. For simplicity of implementation, the argument list seen
here includes the \f[I]pid\fP and \f[I]pgid\fP arguments.
.PP
The System V \f[CW]getpgid()\fP semantics can be obtained by calling
\f[CW]setpgrp(0, 0)\fP on systems with the BSD version, and this is the
API for libexplain, even on systems that do not use the BSD API.
.\" ----------------------------------------------------
.SH RETURN VALUE
The \f[B]explain_setpgrp_or_die\fP function only returns on success, see
\f[I]setpgrp\fP(2) for more information. On failure, prints an explanation
and exits, it does not return.
.PP
The \f[B]explain_setpgrp_on_error\fP function always returns the value
return by the wrapped \f[I]setpgrp\fP(2) system call.
.\" ----------------------------------------------------
.SH EXAMPLE
The \f[B]explain_setpgrp_or_die\fP function is intended to be used in a
fashion similar to the following example:
.RS
.ft CW
.nf
explain_setpgrp_or_die(pid, pgid);
.fi
.ft R
.RE
.\" ----------------------------------------------------
.SH SEE ALSO
.TP 8n
\f[I]setpgrp\fP(2)
set process group
.TP 8n
\f[I]explain_setpgrp\fP(3)
explain \f[I]setpgrp\fP(2) errors
.TP 8n
\f[I]exit\fP(2)
terminate the calling process
.\" ----------------------------------------------------
.SH COPYRIGHT
.so etc/version.so
.if n .ds C) (C)
.if t .ds C) \(co
libexplain version \*(v)
.br
Copyright \*(C) 2011 Peter Miller
.\" vim: set ts=8 sw=4 et
|
