sample-lines 1.2.0

Command-line tool to sample lines from a file or stdin without replacement. It runs in one pass without reading the whole input into memory using reservoir sampling.
sample-lines-1.2.0 is not a library.

sample-lines

samp is a fast command-line tool to randomly sample lines from a file or standard input using reservoir sampling. It samples uniformly without replacement.

Good for:

  • Downsampling large datasets
  • Sampling logs for debugging
  • Creating reproducible random subsets of data

Installation

If you have Rust installed, you can install samp with:

cargo install sample-lines

Or build it from source:

git clone https://github.com/stringertheory/sample-lines.git
cd sample-lines
cargo build --release

Usage

samp -n <NUM> [--seed <SEED>] [FILE]

Here are a few examples:

samp --help
cat data.txt | samp -n 10
samp -n 10 data.txt
samp -n 10 < data.txt
samp -n 10 --seed 17 < data.txt
cat data.csv | samp -n 10 --preserve-headers

Options

Option Description
-n <NUM> Number of lines to sample (required)
--seed <SEED> Optional seed for reproducible sampling
-p, --preserve-headers [N] Preserve the first N lines as headers (default: 1 if flag is used)
-h, --help Show help message
--version Show the version number

Testing

cargo clean
cargo build # need binary for testing stdin/stderr
cargo test

License

Licensed under the MIT License.

Contributing

Issues and pull requests welcome! If you have an idea, a feature request, or a bug report, feel free to open an issue or PR.