Using the stdout and stdin with System.IO.runCommand

Question

I am trying to capture the stdin and stdout from runProcess into a string for analysis.

However, setting up the handles seems to be rather difficult. I wandered into GHC.IO.Handle, and that seems to be the logical destination, but it seems that this should be very simple.

Mikhail Glushenkov · Accepted Answer · 2011-10-05T06:04:25.623

5

If you don't need to communicate with the process interactively, the easiest method is to use readProcess:

> readProcess "date" [] []
  "Thu Feb  7 10:03:39 PST 2008\n"

Otherwise, look at runInteractiveProcess - it starts the process and creates pipes that you can write to and read from with e.g. hPutStr/hGetLine.

edited Oct 05 '11 at 06:04

answered Oct 05 '11 at 05:57

Mikhail Glushenkov

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readProcessWithExitCodeSource turns out to be what I was looking for. – Paul Nathan Oct 05 '11 at 06:17

Using the stdout and stdin with System.IO.runCommand

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