Is there function to execute a shell command

[jieyuan-shen]

As a shell script, is there a function to execute a shell command (e.g. "ls", "pwd", etc.), already?

[matz]

Sorry, not yet.

[mattn]

it's easy to implement with popen, i guess.

[amiralles]

Hey @matz! Big fan of your work!

Would the syntax for this feature look something like this?

system('ls') { in, out, err -> ... } | stdout

If so, I could try to implement it. Thanks!

[matz]

What I thought was:

spawn("ls") | stdout                           # can be a producer
stream | spawn("grep foo") | stdout  # and also be a filter
stream | spawn("cat > /tmp/a")         # and a consumer

[amiralles]

Yeah, that's way better. I'll explore that route. Thanks for replying!

…

On Sun, 11 Nov 2018 at 21:17, matz ***@***.***> wrote: What I thought was: spawn("ls") | stdout # can be a producer stream | spawn("grep foo") | stdout # and also be a filter stream | spawn("cat > /tmp/a") # and a consumer — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#136 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACBcdO3GlUNP2aXpsDBPEclAfZ-QEkv4ks5uuL40gaJpZM4GLWz3> .

[amiralles]

I managed to implement the first use-case on my fork (and it seems to work fine so far)

spawn("ls") | stdout    # can be a producer

Now I'm stuck at this one:

stream | spawn("grep foo") | stdout  # and also be a filter

As far as I understand, a stream can be a producer, a consumer, or a filter, but not all at the same time. So, the first question is:

Is it possible for the spawn function to produce different kinds of streams based on their usage?

If so, is there a way to identify how the function is being used (maybe based on the stream parameter or something like that)?

Thanks!