pipe proc

# Pipe commands.
proc ::fptools::pipe args {
    puts $args
    if {[llength $args] == 0} {
        error {wrong # args: should be "pipe script ?script ...?"}
    }

    set varName _

    upvar 1 $varName stepResult
    upvar 1 pipe pipe

    array unset pipe
    set i 0
    foreach command $args {
        set stepResult [uplevel 1 [list eval $command]]
        set pipe($i) $stepResult
        incr i
    }

    set result $stepResult
    return $result
}