krep

A high-performance string search utility for the command line. Fast, multi-threaded, and grep-compatible.

Features

• Smart algorithm selection (Boyer-Moore, KMP, Two-Way, Shift-Or, Aho-Corasick)
• SIMD acceleration (SSE4.2, AVX2, NEON) and memory-mapped I/O
• Multi-threaded search across CPU cores
• POSIX regular expressions and multiple pattern search
• Recursive directory search with globs, exclusions, and .gitignore support
• Grep-compatible context (-A, -B, -C, -n, -o, -c, -l, -L, -q)
• JSON Lines output (--json) for automation
• Colored output

Installation

# macOS (Homebrew)
brew install krep

# From source
git clone https://github.com/davidesantangelo/krep.git
cd krep
make
sudo make install

Requirements: GCC or compatible C compiler, POSIX system (Linux, macOS, BSD), pthread.

Usage

krep [OPTIONS] PATTERN [FILE | DIRECTORY]
krep [OPTIONS] -e PATTERN -e PATTERN ...
krep [OPTIONS] -f FILE               # patterns from file (- for stdin)
krep [OPTIONS] -s PATTERN STRING     # search in a string instead of a file
cat FILE | krep PATTERN

Examples

krep -F "value: 100%" config.ini              # fixed string
krep -r "function" ./project                  # recursive search
krep -r --gitignore "TODO" ./project          # respect .gitignore
krep -r --glob '*.c' --exclude '*/vendor/*' "TODO" .
krep -n -C 2 "panic" app.log                  # line numbers + context
krep -w 'cat' file.txt                        # whole words only
krep -r -l "DeprecatedAPI" .                  # list files with matches
krep -q "required" config.ini                # quiet existence check
krep --json "needle" ./src/main.c             # JSON Lines output
echo 'pattern' | krep -f - target.txt         # patterns from stdin

Options

• -i, --ignore-case Case-insensitive search
• -c, --count Count matching lines only
• -o, --only-matching Print only the matched parts
• -n, --line-number Prefix lines with line numbers
• -A, -B, -C NUM Context after, before, or around matches
• -l, -L Files with / without matches
• -q, --quiet Exit status only
• -e PATTERN Specify pattern(s), repeatable
• -f FILE Read patterns from file (- for stdin)
• -m NUM Max matching lines per file
• -E POSIX extended regex
• -F Fixed strings (default)
• -r, --recursive Recursively search directories
• --glob=GLOB, --exclude=GLOB Include/exclude paths
• --hidden Include hidden files
• --gitignore Respect .gitignore
• --algo=ALGO Force algorithm: auto, bm, kmp, bndm, two
• -t NUM, --threads=NUM Thread count (default: auto)
• -s STRING Search in a string instead of files
• -w, --word-regexp Whole words only
• --json, --jsonl JSON Lines output
• --stats Print summary to stderr
• --color[=WHEN] Color control (always, never, auto)
• --no-simd Disable SIMD
• -v, --version, -h, --help

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Author

• Davide Santangelo - GitHub

License

BSD-2 License - see the LICENSE file for details.