Provided by: libexplain-dev_1.4.D001-13_amd64 
NAME
explain_getsockname - explain getsockname(2) errors
SYNOPSIS
#include <libexplain/getsockname.h>
const char *explain_getsockname(int fildes, struct sockaddr *sock_addr, socklen_t *sock_addr_size);
const char *explain_errno_getsockname(int errnum, int fildes, struct sockaddr *sock_addr, socklen_t
*sock_addr_size);
void explain_message_getsockname(char *message, int message_size, int fildes, struct sockaddr *sock_addr,
socklen_t *sock_addr_size);
void explain_message_errno_getsockname(char *message, int message_size, int errnum, int fildes, struct
sockaddr *sock_addr, socklen_t *sock_addr_size);
DESCRIPTION
These functions may be used to obtain explanations for errors returned by the getsockname(2) system call.
explain_getsockname
const char *explain_getsockname(int fildes, struct sockaddr *sock_addr, socklen_t *sock_addr_size);
The explain_getsockname function is used to obtain an explanation of an error returned by the
getsockname(2) system call. The least the message will contain is the value of strerror(errno), but
usually it will do much better, and indicate the underlying cause in more detail.
The errno global variable will be used to obtain the error value to be decoded.
This function is intended to be used in a fashion similar to the following example:
struct sockaddr sock_addr;
socklen_t sock_addr_size = sizeof(sock_addr);
if (getsockname(fildes, &sock_addr, &sock_addr_size) < 0)
{
fprintf(stderr, "%s\n", explain_getsockname(fildes,
&sock_addr, &sock_addr_size));
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the explain_getsockname_or_die(3) function.
fildes The original fildes, exactly as passed to the getsockname(2) system call.
sock_addr
The original sock_addr, exactly as passed to the getsockname(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the getsockname(2) system call.
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.
Note: This function is not thread safe, because it shares a return buffer across all threads, and many
other functions in this library.
explain_errno_getsockname
const char *explain_errno_getsockname(int errnum, int fildes, struct sockaddr *sock_addr, socklen_t
*sock_addr_size);
The explain_errno_getsockname function is used to obtain an explanation of an error returned by the
getsockname(2) system call. The least the message will contain is the value of strerror(errnum), but
usually it will do much better, and indicate the underlying cause in more detail.
This function is intended to be used in a fashion similar to the following example:
struct sockaddr sock_addr;
socklen_t sock_addr_size = sizeof(sock_addr);
if (getsockname(fildes, &sock_addr, &sock_addr_size) < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_getsockname(err,
fildes, &sock_addr, &sock_addr_size));
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the explain_getsockname_or_die(3) function.
errnum The error value to be decoded, usually obtained from the errno global variable just before this
function is called. This is necessary if you need to call any code between the system call to be
explained and this function, because many libc functions will alter the value of errno.
fildes The original fildes, exactly as passed to the getsockname(2) system call.
sock_addr
The original sock_addr, exactly as passed to the getsockname(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the getsockname(2) system call.
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.
Note: This function is not thread safe, because it shares a return buffer across all threads, and many
other functions in this library.
explain_message_getsockname
void explain_message_getsockname(char *message, int message_size, int fildes, struct sockaddr *sock_addr,
socklen_t *sock_addr_size);
The explain_message_getsockname function may be used to obtain an explanation of an error returned by
the getsockname(2) system call. The least the message will contain is the value of strerror(errno), but
usually it will do much better, and indicate the underlying cause in more detail.
The errno global variable will be used to obtain the error value to be decoded.
This function is intended to be used in a fashion similar to the following example:
struct sockaddr sock_addr;
socklen_t sock_addr_size = sizeof(sock_addr);
if (getsockname(fildes, &sock_addr, &sock_addr_size) < 0)
{
char message[3000];
explain_message_getsockname(message, sizeof(message),
fildes, &sock_addr, &sock_addr_size);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the explain_getsockname_or_die(3) function.
message The location in which to store the returned message. If a suitable message return buffer is
supplied, this function is thread safe.
message_size
The size in bytes of the location in which to store the returned message.
fildes The original fildes, exactly as passed to the getsockname(2) system call.
sock_addr
The original sock_addr, exactly as passed to the getsockname(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the getsockname(2) system call.
explain_message_errno_getsockname
void explain_message_errno_getsockname(char *message, int message_size, int errnum, int fildes, struct
sockaddr *sock_addr, socklen_t *sock_addr_size);
The explain_message_errno_getsockname function may be used to obtain an explanation of an error returned
by the getsockname(2) system call. The least the message will contain is the value of strerror(errnum),
but usually it will do much better, and indicate the underlying cause in more detail.
This function is intended to be used in a fashion similar to the following example:
struct sockaddr sock_addr;
socklen_t sock_addr_size = sizeof(sock_addr);
if (getsockname(fildes, &sock_addr, &sock_addr_size) < 0)
{
int err = errno;
char message[3000];
explain_message_errno_getsockname(message, sizeof(message),
err, fildes, &sock_addr, &sock_addr_size);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre‐packaged as the explain_getsockname_or_die(3) function.
message The location in which to store the returned message. If a suitable message return buffer is
supplied, this function is thread safe.
message_size
The size in bytes of the location in which to store the returned message.
errnum The error value to be decoded, usually obtained from the errno global variable just before this
function is called. This is necessary if you need to call any code between the system call to be
explained and this function, because many libc functions will alter the value of errno.
fildes The original fildes, exactly as passed to the getsockname(2) system call.
sock_addr
The original sock_addr, exactly as passed to the getsockname(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the getsockname(2) system call.
SEE ALSO
getsockname(2)
get socket name
explain_getsockname_or_die(3)
get socket name and report errors
COPYRIGHT
libexplain version 1.4
Copyright (C) 2009 Peter Miller
explain_getsockname(3)