The explain_accept function is
used to obtain an explanation of an error returned by the accept(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:
The above code example is available pre-packaged as the
explain_accept_or_die(3) function.
fildes
The original fildes, exactly as passed to the accept(2) system call.
sock_addr
The original sock_addr, exactly as passed to the accept(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the accept(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.
The explain_errno_accept function
is used to obtain an explanation of an error returned by
the accept(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:
if (accept(fildes, sock_addr, sock_addr_size) < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_accept(err, fildes, sock_addr,
sock_addr_size));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_accept_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 accept(2) system call.
sock_addr
The original sock_addr, exactly as passed to the accept(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the accept(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_accept
void explain_message_accept(char *message, int message_size, int fildes,
struct sockaddr *sock_addr, socklen_t *sock_addr_size);
The explain_message_accept
function may be used to obtain an explanation of an error
returned by the
accept(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:
The above code example is available pre-packaged as the
explain_accept_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 accept(2) system call.
sock_addr
The original sock_addr, exactly as passed to the accept(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the accept(2)
system call.
explain_message_errno_accept
void explain_message_errno_accept(char *message, int message_size,
int errnum, int fildes, struct sockaddr *sock_addr, socklen_t *sock_addr_size);
The explain_message_errno_accept
function may be used to obtain an explanation of an error
returned by the
accept(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:
The above code example is available pre-packaged as the
explain_accept_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 accept(2) system call.
sock_addr
The original sock_addr, exactly as passed to the accept(2) system call.
sock_addr_size
The original sock_addr_size, exactly as passed to the accept(2)
system call.