# pydoc > _bootsubprocess

---
type: CommandReference
command: _bootsubprocess
mode: pydoc
section: 
source: pydoc3
---

## Quick Reference
- `_bootsubprocess.Popen(cmd, env=None)` — spawn a subprocess (used by distutils)
- `_bootsubprocess.check_output()` — run command and capture output (used by _aix_support)

## Name
Basic subprocess implementation for POSIX using only os functions. Only implements features required by setup.py to build C extension modules when subprocess is unavailable.

## Synopsis
python
import _bootsubprocess

class _bootsubprocess.Popen(cmd, env=None)
    # .wait() method

_bootsubprocess.check_output()
## Classes
- `Popen(cmd, env=None)` — spawn a subprocess. Provides `__init__` and `wait` methods. Data descriptors: `__dict__`, `__weakref__`.

## Functions
- `check_output()` — run command and capture output. Used by `_aix_support` in `distutil.util`.