explain_pread_or_die(3)

NAME

explain_pread_or_die - seek and read from a file descriptor and report errors

SYNOPSIS

#include <libexplain/pread.h>
ssize_t explain_pread_or_die(int fildes, void *data, size_t  data_size,
off_t offset);
ssize_t   explain_pread_on_error(int   fildes,   void   *data,   size_t
data_size, off_t offset))

DESCRIPTION

The explain_pread_or_die function is used to call the pread(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_pread(3) function, and then the process terminates by calling exit(EXIT_FAILURE).

The explain_pread_on_error function is used to call the pread(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_pread(3) function, but still returns to the caller.

fildes The fildes, exactly as to be passed to the pread(2) system

call.

data The data, exactly as to be passed to the pread(2) system call.

data_size

The data_size, exactly as to be passed to the pread(2) system call.

offset The offset, exactly as to be passed to the pread(2) system

call.

RETURN VALUE

The explain_pread_or_die function only returns on success, see pread(2) for more information. On failure, prints an explanation and exits, it does not return.

The explain_pread_on_error function always returns the value return by the wrapped pread(2) system call.

EXAMPLE

The explain_pread_or_die function is intended to be used in a fashion similar to the following example:

ssize_t result = explain_pread_or_die(fildes, data, data_size, offset);

SEE ALSO

pread(2)

read from a file descriptor at a given offset

explain_pread(3)

explain pread(2) errors

exit(2) terminate the calling process

COPYRIGHT

libexplain version 0.37
Copyright (C) 2009 Peter Miller

explain_pread_or_die(3)