swap.sh

#!/bin/bash
# Path: /usr/bin/swap
function swap() {
    if [ ! -f "$1" ] || [ ! -f "$2" ]; then return 1; fi
    TMPFILE=/dev/shm/tmp.$$
    dd if="$1"     of=$TMPFILE status=none bs=512K && \
    dd if="$2"     of="$1"     status=none bs=512K && \
    dd if=$TMPFILE of="$2"     status=none bs=512K && \
    ( \
      if [ $? -ne 1 ]; then true; else unlink $TMPFILE && unset $TMPFILE; return 1; fi; \
    ) && \
    sync && \
    unlink $TMPFILE
    unset TMPFILE
}