swab() -- swap bytes

SYNOPSIS

#include <unistd.h>

void swab(const void *src, void *dst, ssize_t nbytes);

The swab() function copies the specified number of bytes from the specified source to the specified destination, exchanging adjacent bytes. The number of bytes should be even. If the number of bytes is odd, swab() copies and exchanges (nbytes-1) bytes and the disposition of the last byte is unspecified. If the source and destination regions overlap, the behavior is unspecified. If the specified number of bytes is negative, swab() does nothing.