### Navigation

- index
- modules |
- next |
- previous |
- Python v2.6 documentation »
- The Python Standard Library »

# Unix Specific Services

The modules described in this chapter provide interfaces to features that are unique to the Unix operating system, or in some cases to some or many variants of it. Here’s an overview:

- `posix` — The most common POSIX system calls
  - Large File Support
  - Notable Module Contents

- `pwd` — The password database

- `spwd` — The shadow password database

- `grp` — The group database

- `crypt` — Function to check Unix passwords

- `dl` — Call C functions in shared objects
  - Dl Objects

- `termios` — POSIX style tty control
  - Example

- `tty` — Terminal control functions

- `pty` — Pseudo-terminal utilities

- `fcntl` — The `fcntl` and `ioctl` system calls

- `pipes` — Interface to shell pipelines
  - Template Objects

- `posixfile` — File-like objects with locking support

- `resource` — Resource usage information
  - Resource Limits
  - Resource Usage

- `nis` — Interface to Sun’s NIS (Yellow Pages)

- `syslog` — Unix syslog library routines

- `commands` — Utilities for running commands

### Navigation

- index
- modules |
- next |
- previous |
- Python v2.6 documentation »
- The Python Standard Library »