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