perl one liners

psuedo grep with perlish regexps

    perl -n -e 'print if m#^\d{1,3}#' somefile        # grep
    perl -n -e 'print unless m#^\d{1,3}#' somefile    # grep -v
    perl -n -e 'print if m#^abc\d{1,3}#i' somefile    # grep -i

replace every occurrence of 'xyz' with 'abc' in somefile

    perl -pi -e 's#xyz#abc#g' somefile

replace every occurrence of 'xyz' in a shell loop

    FILES='this that the-other'
    for F in $FILES ; do perl -pi -e "s#xyz#$F#g" $F

emulate dos2unix and unix2dos

    perl -pi -e 's#\r$##' x.x    # dos2unix
    perl -pi -e 's#$#\r#' x.x    # unix2dos