.lf 1 ./man/man3/explain_setsockopt.3
.\"
.\" 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
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.\" 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.
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.\" along with this program. If not, see .
.\"
.ds n) explain_setsockopt
.cp 0 \" Solaris defaults to ''.cp 1'', sheesh.
.TH explain_setsockopt 3
.SH NAME
explain_setsockopt \- explain setsockopt(2) errors
.if require_index \{
.\}
.SH SYNOPSIS
#include
.sp 0.3
const char *explain_setsockopt(int fildes, int level, int name, void *data,
socklen_t data_size);
.br
const char *explain_errno_setsockopt(int errnum, int fildes, int level,
int name, void *data, socklen_t data_size);
.br
void explain_message_setsockopt(char *message, int message_size, int fildes,
int level, int name, void *data, socklen_t data_size);
.br
void explain_message_errno_setsockopt(char *message, int message_size,
int errnum, int fildes, int level, int name, void *data, socklen_t data_size);
.SH DESCRIPTION
These functions may be used to obtain explanations for
errors returned by the \f[I]setsockopt\fP(2) system call.
.\" ----------------------------------------------------
.SS explain_setsockopt
const char *explain_setsockopt(int fildes, int level, int name, void *data,
socklen_t data_size);
.PP
The \f[B]explain_setsockopt\fP function is
used to obtain an explanation of an error returned by the \f[I]setsockopt\fP(2)
system call. The least the message will contain is the
value of \f[CW]strerror(errno)\fP, but usually it will
do much better, and indicate the underlying cause in more
detail.
.PP
The \f[I]errno\fP global variable will be used to obtain
the error value to be decoded.
.PP
This function is intended to be used in a fashion
similar to the following example:
.RS
.ft CW
.nf
if (setsockopt(fildes, level, name, data, data_size) < 0)
{
fprintf(stderr, "%s\en", explain_setsockopt(fildes,
level, name, data, data_size));
exit(EXIT_FAILURE);
}
.fi
.ft R
.RE
.PP
The above code example is available pre\[hy]packaged as the
\f[I]explain_setsockopt_or_die\fP(3) function.
.TP 8n
\f[I]fildes\fP
The original fildes, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]level\fP
The original level, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]name\fP
The original name, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data\fP
The original data, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data_size\fP
The original data_size, exactly as passed to the \f[I]setsockopt\fP(2)
system call.
.TP 8n
Returns:
The message explaining the error. This message buffer is
shared by all libexplain functions which do not supply a
buffer in their argument list. This will be overwritten
by the next call to any libexplain function which shares
this buffer, including other threads.
.PP
\f[B]Note:\fP
This function is \f[B]not\fP thread safe, because it
shares a return buffer across all threads, and many other
functions in this library.
.\" ----------------------------------------------------
.SS explain_errno_setsockopt
const char *explain_errno_setsockopt(int errnum, int fildes, int level,
int name, void *data, socklen_t data_size);
.PP
The \f[B]explain_errno_setsockopt\fP function
is used to obtain an explanation of an error returned by
the \f[I]setsockopt\fP(2) system call.
The least the message will contain is the value of
\f[CW]strerror(errnum)\fP, but usually it will do much
better, and indicate the underlying cause in more detail.
.PP
This function is intended to be used in a fashion
similar to the following example:
.RS
.ft CW
.nf
if (setsockopt(fildes, level, name, data, data_size) < 0)
{
int err = errno;
fprintf(stderr, "%s\en", explain_errno_setsockopt(err,
fildes, level, name, data, data_size));
exit(EXIT_FAILURE);
}
.fi
.ft R
.RE
.PP
The above code example is available pre\[hy]packaged as the
\f[I]explain_setsockopt_or_die\fP(3) function.
.TP 8n
\f[I]errnum\fP
The error value to be decoded, usually obtained from
the \f[I]errno\fP global variable just before this
function is called. This is necessary if you need to call
\f[B]any\fP code between the system call to be explained
and this function, because many libc functions will alter
the value of \f[I]errno\fP.
.TP 8n
\f[I]fildes\fP
The original fildes, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]level\fP
The original level, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]name\fP
The original name, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data\fP
The original data, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data_size\fP
The original data_size, exactly as passed to the \f[I]setsockopt\fP(2)
system call.
.TP 8n
Returns:
The message explaining the error. This message buffer is
shared by all libexplain functions which do not supply a
buffer in their argument list. This will be overwritten
by the next call to any libexplain function which shares
this buffer, including other threads.
.PP
\f[B]Note:\fP
This function is \f[B]not\fP thread safe, because it
shares a return buffer across all threads, and many other
functions in this library.
.\" ----------------------------------------------------
.SS explain_message_setsockopt
void explain_message_setsockopt(char *message, int message_size, int fildes,
int level, int name, void *data, socklen_t data_size);
.PP
The \f[B]explain_message_setsockopt\fP
function may be used to obtain an explanation of an error
returned by the
\f[I]setsockopt\fP(2) system call.
The least the message will contain is the value of
\f[CW]strerror(errno)\fP, but usually it will do much
better, and indicate the underlying cause in more detail.
.PP
The \f[I]errno\fP global variable will be used to obtain
the error value to be decoded.
.PP
This function is intended to be used in a fashion
similar to the following example:
.RS
.ft CW
.nf
if (setsockopt(fildes, level, name, data, data_size) < 0)
{
char message[3000];
explain_message_setsockopt(message, sizeof(message),
fildes, level, name, data, data_size);
fprintf(stderr, "%s\en", message);
exit(EXIT_FAILURE);
}
.fi
.ft R
.RE
.PP
The above code example is available pre\[hy]packaged as the
\f[I]explain_setsockopt_or_die\fP(3) function.
.TP 8n
\f[I]message\fP
The location in which to store the returned message.
If a suitable message return buffer is supplied, this
function is thread safe.
.TP 8n
\f[I]message_size\fP
The size in bytes of the location in which to
store the returned message.
.TP 8n
\f[I]fildes\fP
The original fildes, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]level\fP
The original level, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]name\fP
The original name, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data\fP
The original data, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data_size\fP
The original data_size, exactly as passed to the \f[I]setsockopt\fP(2)
system call.
.\" ----------------------------------------------------
.SS explain_message_errno_setsockopt
void explain_message_errno_setsockopt(char *message, int message_size,
int errnum, int fildes, int level, int name, void *data, socklen_t data_size);
.PP
The \f[B]explain_message_errno_setsockopt\fP
function may be used to obtain an explanation of an error
returned by the
\f[I]setsockopt\fP(2) system call.
The least the message will contain is the value of
\f[CW]strerror(errnum)\fP, but usually it will do much
better, and indicate the underlying cause in more detail.
.PP
This function is intended to be used in a fashion
similar to the following example:
.RS
.ft CW
.nf
if (setsockopt(fildes, level, name, data, data_size) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_setsockopt(message, sizeof(message),
err, fildes, level, name, data, data_size);
fprintf(stderr, "%s\en", message);
exit(EXIT_FAILURE);
}
.fi
.ft R
.RE
.PP
The above code example is available pre\[hy]packaged as the
\f[I]explain_setsockopt_or_die\fP(3) function.
.TP 8n
\f[I]message\fP
The location in which to store the returned message.
If a suitable message return buffer is supplied, this
function is thread safe.
.TP 8n
\f[I]message_size\fP
The size in bytes of the location in which to
store the returned message.
.TP 8n
\f[I]errnum\fP
The error value to be decoded, usually obtained from
the \f[I]errno\fP global variable just before this
function is called. This is necessary if you need to call
\f[B]any\fP code between the system call to be explained
and this function, because many libc functions will alter
the value of \f[I]errno\fP.
.TP 8n
\f[I]fildes\fP
The original fildes, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]level\fP
The original level, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]name\fP
The original name, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data\fP
The original data, exactly as passed to the \f[I]setsockopt\fP(2) system call.
.TP 8n
\f[I]data_size\fP
The original data_size, exactly as passed to the \f[I]setsockopt\fP(2)
system call.
.\" ----------------------------------------------------
.SH SEE ALSO
.TP 8n
\f[I]setsockopt\fP(2)
get and set options on sockets
.TP 8n
\f[I]explain_setsockopt_or_die\fP(3)
get and set options on sockets and report errors
.\" ----------------------------------------------------
.SH COPYRIGHT
.lf 1 ./etc/version.so
.ds v) 1.4
.ds V) 1.4.D001
.ds Y) 2008, 2009, 2010, 2011, 2012, 2013, 2014
.lf 306 ./man/man3/explain_setsockopt.3
.if n .ds C) (C)
.if t .ds C) \(co
libexplain version \*(v)
.br
Copyright \*(C) 2009 Peter Miller
.\" vim:ts=8:sw=4:et