[Process] Process Builder support for pipe command lines

[cordoval]

Creating an issue here in accordance with alchemy-fr/BinaryDriver#2 . @romainneutron could you please tell me how may we implement this, do i push a failing test for this first so we can pin point the problem? Thanks you rock man!

[romainneutron]

We should know if we want to add support for pipe (|) and redirections operators (>, <, 2>&1 among others ...) in the ProcessBuilder.

I think it's a nice feature, I don't know if we should parse user input or provide methods :

ProcessBuilder::create(['cat', 'error.log'])->pipe(ProcessBuilder::create(['grep', 'proton']));
ProcessBuilder::create(['grep', '-lR', 'proton', '/tmp'])->redirect('>', ProcessBuilder::create('output.log'));

VS

ProcessBuilder::create(['cat', 'error.log', '|', 'grep', 'proton']);
ProcessBuilder::create(['grep', '-lR', 'proton', '/tmp', '>', 'output.log']);

[lyrixx]

I like the first approach. And I think it's easier to implement.

[stof]

I would vote for the pipe method, as this would be BC and fits better with an OO builder.
If we start parsing |, it would break BC as it is currently escaped as an argument.

[fabpot]

definitely the first approach.

[cordoval]

ping @jakzal could you please label this issue as [Process]?

[cordoval]

thanks @jakzal

[cryptiklemur]

Any way to do this now?

[cordoval]

@stof @lyrixx @romainneutron @fabpot do you think when this will happen? it is kind of blocking, right now we are working with @aequasi hard to integrate Gush and Bldr.io bldr-io/gush-block#2 to create macro flows and if we have this feature we can do more dynamic things 💃

Thanks a lot guyz /o/ :+1: :baby:

[cryptiklemur]

I'm sure there are also a lot of other people that would benefit from this :)

[mattjanssen]

👍 Would love to see this. I can't use the builder as often without it.

[gbirke]

I'd love to have this. The taskphp Process plugin would also benefit from that because it does no longer need to collect the whole output.

[piotrplenik]

In PR #11971 I've suggest implementation of pipe ("|") functionality.

[romainneutron]

This feature request makes sense

[cryptiklemur]

I think he closed it because it gets resolved by #11972

[dshiryaev-plesk]

Is there a way to do this now ?

[sstok]

You can use \Symfony\Component\Process\ProcessUtils::escapeArgument to escape the arguments, but that's deprecated 😐 OK...

You can always use a string, but you will need to manually escape the arguments.
https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36#sanitizing-input-for-safe-shell-parsing
https://github.com/johnstevenson/winbox-args

[nicolas-grekas]

@sstok NOOOoooo :)
Do never manually escape args, that's a very bad practice.
Just use "prepared" command lines (>=3.3):

$p = new Process('cmd1 "$VAR1" | cmd2 "$VAR2"');
$p->run(null, array('VAR1' => 'value1', 'VAR2' => 'value2'));

[dshiryaev-plesk]

Thank you!

[sstok]

@nicolas-grekas Thanks for the tip 👍

[weitzman]

At least in 3.4, the 2nd argument to run() is an array of env variables, not replacements. Has the recommended approach changed?

[nicolas-grekas]

Nope, replacement has always been preformed by the shell, using env vars yes.

[staabm]

@sstok NOOOoooo :)
Do never manually escape args, that's a very bad practice.
Just use "prepared" command lines (>=3.3):

$p = new Process('cmd1 "$VAR1" | cmd2 "$VAR2"');
$p->run(null, array('VAR1' => 'value1', 'VAR2' => 'value2'));

@nicolas-grekas this no longer works on symfony/process 4.x. strings are not longer allowed for the command - arrays are expected. how should those args be passed instead then?

[lyrixx]

$process = Process::fromShellCommandline('my_command "$MY_VAR"');
$process->run(null, ['MY_VAR' => $theValue]);