[Newbies] PipeableOSProcess incremental output
David T. Lewis
lewis at mail.msen.com
Fri Oct 28 13:04:08 UTC 2011
On Thu, Oct 27, 2011 at 04:58:34PM -0700, Sean P. DeNigris wrote:
> How do I get the output and error of a PipeableOSProcess command line-by-line
> as it comes, like CommandShell does?
In PipeableOSProcess, the output stream is #pipeFromOutput and
the error stream is #errorPipelineStream. For example:
proc := PipeableOSProcess command: 'ls -l * NOSUCHFILE'.
out := proc pipeFromOutput.
err := proc errorPipelineStream.
>From any of these streams you can read character by character
with #next, or you can read the entire contents of the stream
with #upToEnd or #upToEndOfFile. On a unix system, lines of
output in a pipe will usually be separated by line feed characters,
so you can read character by character looking for a Character lf.
But actually you do not even need to access those streams
directly, because PipeableOSProcess itself behaves like a stream.
You can read output directly from a PipeableOSProcess with
#next, #next:, #upToEnd, #upToEndOfFile, #errorUpToEnd, and
To illustrate the idea, one way to get the output of a command
line by line as follows:
(PipeableOSProcess command: 'ls -l')
upToEndOfFile findTokens: String lf
> I found #setNonBlockingOutput for the output, but "pipeFromError
> setNonBlocking" doesn't seem to do the same for the errors.
In PipeableOSProcess this is all handled automatically, so
you can just use the output and error streams as described
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