Subprocess Types Table

Xonsh has a few different ways to launch subprocesses, each with their own unique interface depending on your need. The following table is a quick reference for the different suprocesses. The columns have the following meaning:

Type

The syntax for an example subprocess cmd.

Output

Whether the output is streamed to stdout/stderr. If “captured”, the output is not streamed as the cmd runs. If “uncaptured”, the output is streamed.

Returns

The type of the object returned by the subprocess executions. For example, if you were to run p = $(cmd), the return column gives the type of p.

Notes

Any comments about the subprocess.

Type	Output	Returns	Notes
cmd	Uncaptured	HiddenCommandPipeline	The same as ![cmd]
![cmd]	Uncaptured	HiddenCommandPipeline
$[cmd]	Uncaptured	None
!(cmd)	Captured	CommandPipeline
$(cmd)	Captured	str	stdout is returned