Unable to pipe Bash output to other programs

[RaeesBhatti]

I'm unable to spawn Bash from NodeJS. If you try to, it will return this error: Error: 0x80070057

How to reproduce:

• Install NodeJS
• Run node in CMD
• Type:

cp = require('child_process');
proc = cp.spawnSync('cmd', ['/c', 'bash -c "ls"'], {encoding: 'utf8'}).output

It outputs:

[ null, 'Error: 0x80070057\r\r\n', '' ]

[justinhixson]

This is actually a pretty interesting one. in Python, for example, I can spawn bash just fine with the subprocess module, but only under certain circumstances. consider the following script:

import subprocess
subprocess.run(["bash","-c","ls"])

this is saved as bash.py

c:\>python bash.py works

c:\>python
>>import subprocess;
>>subprocess.run(["bash","-c","ls"])

also works

however, I found it very interesting that

C:\>echo import subprocess; subprocess.run(["bash","-c","ls"]); | python 

does NOT work. same Error: 0x80070057

(note that something like

C:\>echo import subprocess; subprocess.run(["notepad"]); | python

does indeed work.)

I was using python 3.5 for these tests.

I am sure that it is much more complicated than this, but bash.exe seems to be really, really offended by stream redirection with pipes. that doesn't clearly explain why OP is having a problem with node.js, but note that this is exactly the same error that you would get if you ever try to pipe something into bash.exe at all. for instance:

C:\Users\Justin>type rocks.sh
#!/bin/bash
echo "bash on Windows ????!" | sed 's/????/rocks/g'

C:\Users\Justin>bash rocks.sh
bash on Windows rocks!

C:\Users\Justin>type rocks.sh | bash
Error: 0x80070057

C:\Users\Justin>type rocks.sh | bash -c "sh"
Error: 0x80070057

C:\Users\Justin>bash -c "sh"
# rocks.sh
bash on Windows rocks!
# exit

C:\Users\Justin>bash -c "sh" < rocks.sh
Error: 0x80070057

C:\Users\Justin>echo "./rocks.sh" | bash -c "sh"
Error: 0x80070057

[RaeesBhatti]

Can confirm. This is a problem with bash having problems with output piping. If I specify { stdio: 'inhert' }, it works but that way I then have no way of getting that data. { stdio: 'pipe' } produces the error above

[MadcowD]

I've made a related issue in Bash on Windows. #312

[bitcrazed]

Thanks for the issue report - this was fixed in Creators Update.

[justinhixson]

Thank you so much for this! This has been my most anticipated feature for the Linux Subsystem since i first heard about it. I am enjoying it immensely, and can confirm that it now works exactly as one would imagine it would. Thanks again!!!!!