e= case $1 in -*) e=$1 shift;; esac if test $# = 3 -a -f $1 -a -f $2 -a -f $3 then : else echo usage: diff3 file1 file2 file3 1>&2 exit fi trap "rm -f /tmp/d3[ab]$$" 0 1 2 13 15 diff $1 $3 >/tmp/d3a$$ diff $2 $3 >/tmp/d3b$$ /usr/lib/diff3 $e /tmp/d3[ab]$$ $1 $2 $3