mgrep

A simple clone of grep (ASCII only), written in Zig (0.13.0). With a simplistic epsilon-nfa regex engine implemented.

Credits to this tutorial: https://rhaeguard.github.io/posts/regex/

Usage

Unit tests:

zig build test

Build:

zig build --release=safe

Run mgrep on a file:

./zig-out/bin/mgrep "pattern" filename.txt

Run mgrep on multiple files/directories with multiple configs:

./zig-out/bin/mgrep -hn "pattern" src/ filename2.txt

Features

mgrep flags:

Flag	Desc.
-c	Prints count of lines containing pattern (not count of matched patterns)
-h	Displays filename next to matched line
-l	Prints list of files containing at least 1 line with a match
-n	Displays line number next to matched line
-v	Matches based on negation of pattern

regex features

Pattern	Desc.
[abc]	A single character of a, b or c
[^abc]	A single character that is not a, b or c
[a-z]	A single character in the range a to z
[^a-z]	A single character not in the range a to z
[a-zA-Z]	A single character in the range a to z and A to Z
.	Any single character
a|b	Either a or b
\s	A whitespace character
\S	A non-whitespace character
\d	A digit character
\D	A non-digit character
\w	A word character
\W	A non-word character
a*	Zero or more of a
a+	One or more of a
a?	Zero or one of a
a{3}	Exactly three of a
a{3,}	Three or more of a
a{,3}	Zero to three of a
a{3,5}	Between three to five of a
a*?	Lazy quantifier

Unavailable features

• Anchors
• Backreferencing
• Possessive matching