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.\"
.\" libexplain - Explain errno values returned by libc functions
.\" Copyright (C) 2009, 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
.\" 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_pread_or_die
.cp 0 \" Solaris defaults to ''.cp 1'', sheesh.
.TH explain_pread_or_die 3
.SH NAME
explain_pread_or_die \- seek and read from a file descriptor and report errors
.if require_index \{
.XX "explain_pread_or_die(3)" \
"read from a file descriptor at a given offset and report errors"
.\}
.SH SYNOPSIS
#include <libexplain/pread.h>
.sp 0.3
ssize_t explain_pread_or_die(int fildes, void *data, size_t data_size,
off_t offset);
.br
ssize_t explain_pread_on_error(int fildes, void *data, size_t data_size,
off_t offset))
.SH DESCRIPTION
The \f[B]explain_pread_or_die\fP function is used to call the
\f[I]pread\fP(2) system call. On failure an explanation will be printed to
\f[I]stderr\fP, obtained from the \f[I]explain_pread\fP(3) function, and
then the process terminates by calling \f[CW]exit(EXIT_FAILURE)\fP.
.PP
The \f[B]explain_pread_on_error\fP function is used to call the
\f[I]pread\fP(2) system call. On failure an explanation will be printed to
\f[I]stderr\fP, obtained from the \f[I]explain_pread\fP(3) function, but
still returns to the caller.
.TP 8n
\f[I]fildes\fP
The fildes, exactly as to be passed to the \f[I]pread\fP(2) system call.
.TP 8n
\f[I]data\fP
The data, exactly as to be passed to the \f[I]pread\fP(2) system call.
.TP 8n
\f[I]data_size\fP
The data_size, exactly as to be passed to the \f[I]pread\fP(2) system call.
.TP 8n
\f[I]offset\fP
The offset, exactly as to be passed to the \f[I]pread\fP(2) system call.
.\" ----------------------------------------------------
.SH RETURN VALUE
The \f[B]explain_pread_or_die\fP function only returns on success, see
\f[I]pread\fP(2) for more information. On failure, prints an explanation
and exits, it does not return.
.PP
The \f[B]explain_pread_on_error\fP function always returns the value return
by the wrapped \f[I]pread\fP(2) system call.
.\" ----------------------------------------------------
.SH EXAMPLE
The \f[B]explain_pread_or_die\fP function is intended to be used in a
fashion similar to the following example:
.RS
.ft CW
.nf
ssize_t result = explain_pread_or_die(fildes, data, data_size, offset);
.fi
.ft R
.RE
.\" ----------------------------------------------------
.SH SEE ALSO
.TP 8n
\f[I]pread\fP(2)
read from a file descriptor at a given offset
.TP 8n
\f[I]explain_pread\fP(3)
explain \f[I]pread\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) 2009 Peter Miller
.\" vim: set ts=8 sw=4 et
|
