macOS
Homebrewverified · 100%
brew install peglocal Homebrew formula metadata
MacPortsverified · 94%
sudo port install pegMacPorts ports tree · devel/peg/Portfile · source: api.github.com
brew
Install peg with Homebrew, apk, apt, MacPorts, Nix, pacman, zypper
Program to perform pattern matching on text. Version 0.1.19 via Homebrew; verified 2026-06-14.
install
Additional install commands
Linux
Alpine Linux apkverified · 92%
sudo apk add pegAlpine Linux edge package indexes · peg · source: dl-cdn.alpinelinux.org
Debian aptverified · 92%
sudo apt install pegDebian stable package indexes · peg · source: deb.debian.org
Nixverified · 92%
nix profile install nixpkgs#pegnixpkgs package indexes · pkgs/by-name/pe/peg/package.nix · source: api.github.com
Arch Linux pacmanverified · 92%
sudo pacman -S pegArch Linux sync databases · peg · source: geo.mirror.pkgbuild.com
openSUSE zypperverified · 92%
sudo zypper install pegopenSUSE Tumbleweed package metadata · peg · source: download.opensuse.org
overview
Package summary
Program to perform pattern matching on text
Project links
Commands and aliases
- leg
- peg
history
Project history and usage
peg and leg are recursive-descent parser generators for C. They process Parsing Expression Grammars and generate C parsers, with `peg` following Bryan Ford's original PEG syntax and `leg` using conventions intended as an alternative to lex and yacc.
Project history
Ian Piumarta's official page lists peg/leg as tools for generating recursive-descent parsers from Parsing Expression Grammars. The first public release in the official version history is 0.1.1 on 2007-05-15.
The manual page explains that peg reads grammar files or standard input and generates C source defining `yyparse()`, while leg uses a syntax intended to make it attractive to users familiar with lex and yacc workflows.
The official version history shows steady maintenance through 0.1.19 stable in 2023, including reentrant parsing support, error actions, UTF-8 fixes, C++ support improvements, and Windows/Mac build files.
Adoption history
peg/leg spread through Unix-like package managers as a small C parser-generation tool: the input metadata lists Homebrew, Debian, Ubuntu, Arch, MacPorts, Nix, Alpine, and openSUSE package names.
Its niche is smaller than yacc-family tools, but it remains useful where a project wants PEG-style ordered choice, unlimited backtracking, and combined scanning and parsing in generated C.
How it is used
Typical use is to run `peg` or `leg` over a grammar file and compile or include the generated C source in a client program.
The official manual documents options such as `-o` for output file selection, `-P` for suppressing `#line` directives, `-v` for verbose mode, and `-V` for version output.
Why package nerds care
peg/leg is package-manager-friendly because it is a compact C command-line tool with a stable manual page, source tarballs, and a long version history.
For package nerds it is also a useful contrast with lex/yacc: a small PEG-based generator that produces embeddable C parsers without requiring a larger parser framework.
Timeline
- 2007-05-15: First public release, 0.1.1.
- 2013-06-03: 0.1.11 added error actions, C++ support improvements, and Win32/Mac build files.
- 2016-07-22: 0.1.18 added the `-P` option to disable `#line` directives.
- 2023-03-06: 0.1.19 stable added experimental re-entrant parsing through `yyparsefrom_r()`.
- 2023-11-19: 0.1.20 development version listed with experimental inline-action variables and semantic values.
Related projects
- Bryan Ford's 2004 Parsing Expression Grammars paper is the formal grammar reference cited by the official page.
- lex and yacc are the comparison point used by the official page and manual.
Sources
- https://www.piumarta.com/software/peg
- https://www.piumarta.com/software/peg/peg.1.html
- source_facts.package-manager
security posture
Risk level: green
narrow executable package without higher-risk signals.
Risk classifier
green risk · low confidence · appliance
Why
- narrow executable package without higher-risk signals
Signals
- metadata:no-higher-risk-signals
Install behavior
- No Homebrew post-install hook is recorded in formula metadata.
- Homebrew bottle metadata is available for 10 platform targets.
Recommended review
Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.
executables
Installed executables
| Command | Kind | Exposure | Note |
|---|---|---|---|
leg | cli | global executable | |
peg | cli | global executable |
freshness
Version and freshness
These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.
page generated2026-07-08
manager version0.1.19
manager updated2026-06-14
local dataok
upstreamnot checked
latest detectednot detected
https://www.piumarta.com/software/peg/
- infoRelease/tag comparison is only available for GitHub repositories.https://www.piumarta.com/software/peg/none confidence
install metadata
Package metadata
| Package key | brew:peg |
|---|---|
| Version | 0.1.19 |
| Package manager | Homebrew |
| Package manager page | https://formulae.brew.sh/formula/peg |
| Homepage | https://www.piumarta.com/software/peg/ |
| Upstream docs | https://www.piumarta.com/software/peg |
| License | MIT |
| Source archive | https://www.piumarta.com/software/peg/peg-0.1.19.tar.gz |
| Last updated | 2026-06-14T14:47:59+02:00 |
| Pulse | updated |
| Bottle | available (on arm64_linux, arm64_monterey, arm64_sequoia, arm64_sonoma, arm64_tahoe, arm64_ventura, monterey, sonoma, ventura, x86_64_linux) |
| Homebrew post-install | not defined |
| Service | none declared |
registry facts
Source database details
| Source Database | Homebrew formula API |
|---|---|
| Tap | homebrew/core |
| Full Name | peg |
| Aliases |
|
| Version Scheme | 0 |
| Revision | 0 |
| Bottle Stable Root URL | https://ghcr.io/v2/homebrew/core |
| Deprecated | no |
| Disabled | no |
| Keg Only | no |
| URL Keys |
|
source database matches
Other package-manager records
Matches are pulled from external package-manager indexes and kept separate from local Automic Vault package links.
Debian apt95%
peg 0.1.20+really0.1.18-1
recursive-descent parser generators for C
https://piumarta.com/software/peg/
sudo apt install peg- Section: devel
- Architecture: amd64
- 1 dependencies
- normalized package name match
- Matched by: Peg
Nix95%
peg
nix profile install nixpkgs#peg- normalized package name match
- Matched by: Peg
Ubuntu apt95%
peg 0.1.18-1build1
recursive-descent parser generators for C
http://piumarta.com/software/peg/
sudo apt install peg- Section: universe/devel
- Architecture: amd64
- 1 dependencies
- normalized package name match
- Matched by: Peg
apk95%
peg 0.1.18-r1
Recursive-descent parser generators for C
https://www.piumarta.com/software/peg/
sudo apk add peg- License: MIT
- Architecture: x86_64
- Source Package: peg
- 1 dependencies
- 1 provides
- normalized package name match
- Matched by: Peg
apk95%
peg-doc 0.1.18-r1
Recursive-descent parser generators for C (documentation)
https://www.piumarta.com/software/peg/
sudo apk add peg-doc- License: MIT
- Architecture: x86_64
- Source Package: peg
- normalized package name match
- Matched by: Peg
pacman95%
peg 0.1.19-1
recursive-descent parser generators for C
http://piumarta.com/software/peg/
sudo pacman -S peg- License: MIT
- Architecture: x86_64
- normalized package name match
- Matched by: Peg
zypper95%
peg 0.1.20-1.7
Recursive-Descent parser generators for C
https://piumarta.com/software/peg/
sudo zypper install peg- License: MIT
- Category: Development/Tools/Building
- Architecture: x86_64
- Source Package: peg
- 1 dependencies
- 1 provides
- normalized package name match
- Matched by: Peg
MacPorts95%
peg
sudo port install peg- normalized package name match
- Matched by: Peg
source trail
Generated from repository data
This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.
Combined YAML source
View the package source record on GitHub.
Used sources
- Geiger risk classifier
- Nucleus package database
- av.db category and tag curation
- cross-ecosystem install command graph
- curated package history
- external package-manager database matches
- package relationship graph
- package version freshness
- package-page enrichment