redirect stdout to a variable in M and NOT to a file

Thank you for the help, here's what I used and did essentially:

    S TRSTR="<tr><td><span>one</span></td><td>two</td></tr>"

    S CMD="node ../pathToNodejsFile/file.js """_TRSTR_""""
    S DEV="|CPIPE|1"
    S EMPTY=0
    open DEV:CMD:0 
    while EMPTY<3 {
        use DEV read line
        set EMPTY=$s($l(line):0,1:$i(EMPTY))
        I line'=""  D
        . use 0 write line,! ; use 0 makes the write go to the default device - if you pass in an IO device you could say `use IO write line` and output to the IO device you have opened if you need to output somewhere other than the default terminal
    }
    use 0 
    close DEV

This is awesome, thank you for sharing! I was able to accomplish my use case with pipes, but this would work if I couldnt figure pipes out

Thanks again