# Debian Almquist shell

> smaller version of Bash aiming for POSIX compliance

**Wikidata**: [Q1144911](https://www.wikidata.org/wiki/Q1144911)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Debian_Almquist_shell)  
**Source**: https://4ort.xyz/entity/debian-almquist-shell

## Summary
Debian Almquist shell (dash) is a smaller, POSIX-compliant Unix shell designed as a lightweight alternative to Bash. It is a direct descendant of the NetBSD version of the Almquist shell (ash) and is widely used in Debian-based systems as the default shell for system scripts and init systems.

## Key Facts
- **Alias**: dash
- **License**: BSD licenses
- **Latest stable version**: 0.5.11.1 (released 2020-07-08)
- **Operating system**: Unix-like systems
- **Inspired by**: Almquist shell (ash)
- **Package availability**: Included in Debian, Ubuntu, Fedora, Arch Linux, and other distributions
- **Source code**: Hosted on the Linux kernel Git repository
- **Website**: http://gondor.apana.org.au/~herbert/dash/
- **Mailing list archives**: Available at https://www.spinics.net/lists/dash/ and https://www.mail-archive.com/dash@vger.kernel.org/

## FAQs
### Q: What is the difference between dash and Bash?
A: Dash is a smaller, faster shell designed for POSIX compliance, making it ideal for system scripts and init systems. Bash, on the other hand, is more feature-rich and user-friendly but larger and slower.

### Q: Why is dash used in Debian and Ubuntu?
A: Dash is used as the default shell for system scripts and init systems in Debian and Ubuntu due to its lightweight nature and strict POSIX compliance, ensuring reliability and consistency.

### Q: How does dash compare to other shells like Zsh or Fish?
A: Dash is a minimalist shell focused on POSIX compliance and performance, whereas Zsh and Fish are more feature-rich and interactive, catering to user convenience rather than system efficiency.

### Q: Is dash compatible with Bash scripts?
A: Dash is mostly compatible with Bash scripts, but it may behave differently due to POSIX compliance. Some scripts may need adjustments to work correctly.

### Q: How can I install dash on my system?
A: Dash is available in most package managers. For example, on Debian-based systems, you can install it with `sudo apt install dash`.

## Why It Matters
Debian Almquist shell (dash) plays a crucial role in Unix-like operating systems, particularly in Debian and Ubuntu, where it serves as the default shell for system scripts and init systems. Its lightweight design and strict adherence to POSIX standards make it highly reliable for critical system operations. By being a smaller and faster alternative to Bash, dash ensures that system scripts and processes run efficiently, contributing to the overall stability and performance of the operating system. Its widespread adoption in major distributions highlights its importance in the Unix ecosystem, where reliability and efficiency are paramount.

## Notable For
- **Lightweight and fast**: Designed to be smaller and faster than Bash, making it ideal for system scripts and init systems.
- **POSIX compliance**: Strict adherence to POSIX standards ensures compatibility and reliability across different Unix-like systems.
- **Default shell in Debian and Ubuntu**: Used as the default shell for system scripts and init systems in these distributions.
- **Open-source and free software**: Distributed under BSD licenses, allowing users to freely run, study, change, and distribute it.
- **Direct descendant of ash**: Inherits the simplicity and efficiency of the original Almquist shell while adding modern features.

## Body
### Overview
Debian Almquist shell (dash) is a minimalist Unix shell designed for POSIX compliance. It is a direct descendant of the NetBSD version of the Almquist shell (ash) and is widely used in Debian-based systems as the default shell for system scripts and init systems.

### Development and Releases
- **Initial development**: Dash was developed as a smaller, faster alternative to Bash.
- **Latest stable version**: 0.5.11.1 (released 2020-07-08).
- **Source code**: Hosted on the Linux kernel Git repository at https://git.kernel.org/pub/scm/utils/dash/dash.git.

### Features and Compatibility
- **POSIX compliance**: Ensures compatibility and reliability across different Unix-like systems.
- **Lightweight**: Smaller and faster than Bash, making it ideal for system scripts and init systems.
- **Script compatibility**: Mostly compatible with Bash scripts, but may behave differently due to POSIX compliance.

### Distribution and Availability
- **Package availability**: Included in Debian, Ubuntu, Fedora, Arch Linux, and other distributions.
- **Package managers**: Available via `apt`, `dnf`, `pacman`, and other package managers.
- **Installation**: Can be installed with commands like `sudo apt install dash` on Debian-based systems.

### Community and Support
- **Website**: http://gondor.apana.org.au/~herbert/dash/
- **Mailing list archives**: Available at https://www.spinics.net/lists/dash/ and https://www.mail-archive.com/dash@vger.kernel.org/.
- **Documentation**: Includes a man page (`dash.1`) and various documentation files in the source code repository.

### Significance
- **Default shell in Debian and Ubuntu**: Used as the default shell for system scripts and init systems, ensuring reliability and efficiency.
- **Open-source and free software**: Distributed under BSD licenses, allowing users to freely run, study, change, and distribute it.
- **Direct descendant of ash**: Inherits the simplicity and efficiency of the original Almquist shell while adding modern features.

## References

1. [COPYING](https://git.kernel.org/pub/scm/utils/dash/dash.git/tree/COPYING?h=v0.5.11.5)
2. [dash_0.5.7.orig.tar.gz](http://http.debian.net/debian/pool/main/d/dash/dash_0.5.7.orig.tar.gz)
3. [The dash Open Source Project on Open Hub: Languages Page. Open Hub](https://www.openhub.net/p/dash/analyses/latest/languages_summary)
4. [Source](http://gondor.apana.org.au/~herbert/dash/files/)
5. [Release 0.5.9.1.](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=afe0e0152e4dc12d84be3c02d6d62b0456d68580)
6. [Release 0.5.10.2.](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?h=v0.5.10.2&id=0e6a3d20816365821fa9ff8f8c6d7bdf915ee3c8)
7. [Release 0.5.11](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=39279293fa358fa8bd681f8ae27bdf11d3a66b53)
8. [Release 0.5.11.1](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=e80bd04d6ee5d40859db8c34d80198e19bf2032d)
9. [ChangeLog.O](https://git.kernel.org/pub/scm/utils/dash/dash.git/tree/ChangeLog.O?id=dd9ef66a805087b871e7ed)
10. [ChangeLog](https://git.kernel.org/pub/scm/utils/dash/dash.git/tree/ChangeLog?id=dd9ef66a805087b871e7e#n782)
11. [Release 0.5.11.3.](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=9e0f6a7745bb8de34baf65b1e382334f8a317cb7)
12. [Release 0.5.11.4](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=efc7765b5d7a4dcd23dbf8fbde35a843f5f222ca)
13. [Release 0.5.11.5](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=663e4c875840363356b2ed05e5539b1422c25e6b)
14. [Source](https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?h=v0.5.12&id=4bbf8721a3ac6401ced6a0454956801f6ba37256)
15. Freebase Data Dumps. 2013
16. [Source](http://gondor.apana.org.au/~herbert/dash/)
17. [Source](http://vger.kernel.org/vger-lists.html#dash)