test Pipe:
    node n
    shell on n as sh:
        echo abcd | grep -o '[bc]*'
        echo abcd | grep -o '[bcd]*' | grep -o '[ab]*'


test Redirect:
    node n
    shell on n as sh:
        echo a > file
        echo b > file
        echo c >> file
        echo x
        cat file
        echo y
        cat < file
        echo z

test PipeRedirect:
    node n
    shell on n as sh:
        echo abcdefghi | grep -o '[b-h]*' | grep -o '[a-g]*' > file
        cat < file | grep -o '[acegi]' | cat > file2
        cat file2 - < file