source: vendor/bash/3.1-p17/tests/cprint.tests

#
# a nonsense script and shell function to test out the command printing code
#
tf()
{
        # simple command with redir
        echo this is ${0##*/} > /dev/null

        # pipeline
        echo a | cat - > /dev/null

        test -f ${0##*/} && echo ${0##*/} is a regular file
        test -d ${0##*/} || echo ${0##*/} is not a directory

        echo a ; echo b ; echo c

        echo background >/dev/null &

        ( exit 1 )
        echo $?

        { echo a ; }

        i=0
        while (( i < 3 )); do
                test -r /dev/fd/$i
                i=$(( i + 1 ))
        done

        [[ -r /dev/fd/0 && -w /dev/fd/1 ]] || echo oops > /dev/null

        for name in $( echo 1 2 3 ); do
                test -r /dev/fd/$name
        done

        if [[ -r /dev/fd/0 && -w /dev/fd/1 ]] ; then
                echo ok > /dev/null
        elif (( 7 > 40 )) ; then
                echo oops
        else
                echo done
        fi > /dev/null

        case $PATH in
        *$PWD*) echo \$PWD in \$PATH ;;
        *)      echo \$PWD not in \$PATH ;;
        esac > /dev/null

        while false; do echo z; done > /dev/null

        until true; do echo z ; done > /dev/null

        echo \&\|'()' \{ echo abcde \; \}
        # when not in POSIX mode, we can have weirdly-named functions
        eval fu\%nc'()' \{ echo abcde \; \}
        type fu\%nc
}

tf2()
{
        ( { time -p echo a | cat - > /dev/null ; } ) 2>&1
}

type tf
type tf2

tf