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