22 changed files with 813 additions and 471 deletions
--- a/.forgejo/workflows/push-next.yml
+++ b/.forgejo/workflows/push-next.yml
@ -0,0 +1,52 @@
+name: Rust
+
+on:
+  push:
+    branches: ["next"]
+  pull_request:
+    branches: ["main"]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: docker
+
+    strategy:
+      matrix:
+        toolchain:
+          - name: stable
+          - name: nightly
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Format
+        uses: https://git.kemitix.net/kemitix/rust@v2.1.0
+        with:
+          args: ${{ matrix.toolchain.name }} cargo fmt --all -- --check
+
+      # - name: Machete
+      #   uses: https://github.com/bnjbvr/cargo-machete@v0.6.2
+
+      - name: Clippy
+        uses: https://git.kemitix.net/kemitix/rust@v2.1.0
+        with:
+          args: ${{ matrix.toolchain.name }} cargo clippy
+
+      - name: Build
+        uses: https://git.kemitix.net/kemitix/rust@v2.1.0
+        with:
+          args: ${{ matrix.toolchain.name }} cargo build
+
+      - name: Test
+        uses: https://git.kemitix.net/kemitix/rust@v2.1.0
+        with:
+          args: ${{ matrix.toolchain.name }} cargo test --no-fail-fast
+
+      - name: Integration
+        uses: https://git.kemitix.net/kemitix/rust@v2.1.0
+        with:
+          args: ./test.sh
--- a/.gitattributes
+++ b/.gitattributes
@ -1,6 +0,0 @@
-* text=auto
-*.zig text eol=lf
-zig.mod text eol=lf
-zigmod.* text eol=lf
-zig.mod linguist-language=YAML
-zig.mod gitlab-language=yaml
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@ -1,27 +0,0 @@
-name: CI
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-  workflow_dispatch:
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        zig: [ 0.9.0, master]
-    steps:
-      - uses: actions/checkout@v2
-      - name: Setup Zig
-        uses: goto-bus-stop/setup-zig@v1.3.0
-        with:
-          version: ${{ matrix.zig }}
-      - run: zig version
-      - run: zig env
-      - uses: nektro/actions-setup-zigmod@v1
-      - run: zigmod ci
-      - run: zig build test
-      - run: zig build
-      - run: cp zig-out/bin/skip .
-      - run: ./test.sh
--- a/.gitignore
+++ b/.gitignore
@ -1,7 +1,3 @@
-zig-cache/
-zig-out/
-.zigmod
-deps.zig
-/test.in
-/test.out
-/test.expect
+/target
+dist/
+input.txt
--- a/.woodpecker.yml
+++ b/.woodpecker.yml
@ -0,0 +1,46 @@
+variables:
+  - &rust_image "docker.io/rust:1.81.0"
+  - &slow_check_paths
+    - path:
+        # rust source code
+        - "crates/**"
+        - "src/**"
+        - "tests/**"
+        - "**/Cargo.toml"
+        - "Cargo.lock"
+        # database migrations
+        - "migrations/**"
+        # config files and scripts used by ci
+        - ".woodpecker.yml"
+
+steps:
+  toml_fmt:
+    image: docker.io/tamasfe/taplo:0.9.3
+    commands:
+      - taplo format --check
+
+  cargo_machete:
+    image: *rust_image
+    commands:
+      - wget https://github.com/cargo-bins/cargo-binstall/releases/latest/download/cargo-binstall-x86_64-unknown-linux-musl.tgz
+      - tar -xvf cargo-binstall-x86_64-unknown-linux-musl.tgz
+      - rm cargo-binstall-x86_64-unknown-linux-musl.tgz
+      - mv cargo-binstall /usr/local/cargo/bin
+      - cargo binstall -y cargo-machete
+      - cargo machete
+
+  ignored_files:
+    image: docker.io/alpine:latest
+    commands:
+      - apk add git
+      - IGNORED=$(git ls-files --cached -i --exclude-standard)
+      - if [[ "$IGNORED" ]]; then echo "Ignored files present:\n$IGNORED\n"; exit 1; fi
+
+  publish_to_crates_io:
+    image: *rust_image
+    commands:
+      - cargo login "$CARGO_REGISTRY_TOKEN"
+      - cargo publish --registry crates-io --no-verify
+    secrets: [cargo_registry_token]
+    when:
+      event: tag
--- a/Cargo.lock
+++ b/Cargo.lock
@ -0,0 +1,223 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anstream"
+version = "0.6.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e2e1ebcb11de5c03c67de28a7df593d32191b44939c482e97702baaaa6ab6a5"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7079075b41f533b8c61d2a4d073c4676e1f8b249ff94a393b0595db304e0dd87"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c75ac65da39e5fe5ab759307499ddad880d724eed2f6ce5b5e8a26f4f387928c"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e28923312444cdd728e4738b3f9c9cac739500909bb3d3c94b43551b16517648"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1cd54b81ec8d6180e24654d0b371ad22fc3dd083b6ff8ba325b72e00c87660a7"
+dependencies = [
+ "anstyle",
+ "windows-sys",
+]
+
+[[package]]
+name = "clap"
+version = "4.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "80c21025abd42669a92efc996ef13cfb2c5c627858421ea58d5c3b331a6c134f"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "458bf1f341769dfcf849846f65dffdf9146daa56bcd2a47cb4e1de9915567c99"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "307bc0538d5f0f83b8248db3087aa92fe504e4691294d0c96c0eabc33f47ba47"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "98cc8fbded0c607b7ba9dd60cd98df59af97e84d24e49c8557331cfc26d301ce"
+
+[[package]]
+name = "colorchoice"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
+
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.78"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2422ad645d89c99f8f3e6b88a9fdeca7fabeac836b1002371c4367c8f984aae"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "skip"
+version = "0.2.1"
+dependencies = [
+ "clap",
+]
+
+[[package]]
+name = "strsim"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ee073c9e4cd00e28217186dbe12796d692868f432bf2e97ee73bed0c56dfa01"
+
+[[package]]
+name = "syn"
+version = "2.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79d9531f94112cfc3e4c8f5f02cb2b58f72c97b7efd85f70203cc6d8efda5927"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"
+
+[[package]]
+name = "utf8parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
--- a/Cargo.toml
+++ b/Cargo.toml
@ -0,0 +1,17 @@
+[package]
+name = "skip"
+version = "0.2.1"
+edition = "2021"
+authors = ["Paul Campbell <pcampbell@kemitix.net>"]
+categories = ["command-line-utilities"]
+description = "Skip lines in a file"
+license = "MIT"
+repository = "https://git.kemitix.net/kemitix/skip"
+keywords = ["skip", "lines", "file", "text", "utility"]
+rust-version = "1.74.1"
+exclude = [".cargo_home"]
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+clap = { version = "4.5", features = ["derive"] }
--- a/21
+++ b/21
@ -1,21 +0,0 @@
-MIT License
-
-Copyright (c) 2021 Paul Campbell
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
--- a/README.md
+++ b/README.md
@ -2,34 +2,29 @@

 Skip part of a file.

-![GitHub release (latest by date)](
-https://img.shields.io/github/v/release/kemitix/skip?style=for-the-badge)
-![GitHub Release Date](
-https://img.shields.io/github/release-date/kemitix/skip?style=for-the-badge)
-
-As `head` will show the top of a file after a number of line,
+As `head` will show the top of a file up-to a number of line,
 so `skip` will do the opposite, and not show the top of the file,
 but will show the rest.

 Additionally, it can check for whole lines matching,
 or for a token being present on the line.

+N.B.: The `skip` crate used to be an implementation of [Skip list](https://en.wikipedia.org/wiki/Skip_list),
+by [Luo Jia / Zhouqi Jiang](https://github.com/luojia65) ([source](https://github.com/luojia65/skip)).
+That crate will be republished as [skip-list](https://crates.io/crates/skip-list) (soon).
+
 ## Usage

 ### Skip a fixed number of lines

 This example reads the file from stdin.

-File: `input.txt`
-
-```text
-line 1
+```bash
+echo "line 1
 line 2
 line 3
-line 4
-```
+line 4" > input.txt

-```bash
 skip 2 < input.txt
 ```

@ -42,20 +37,18 @@ line 4

 ### Skip until a number of matching lines

+The whole line must match.
+
 This example reads the named file.

-File: `input.txt`
-
-```text
-alpha
+```bash
+echo "alpha
 beta
 alpha
 alpha
 gamma
-alpha
-```
+alpha" > input.txt

-```bash
 skip 2 --line alpha input.txt
 ```

@ -67,24 +60,22 @@ gamma
 alpha
 ```

-### Skip lines until a number of tokens as seen
+### Skip lines until a number of tokens are seen
+
+Looks for a string within a line, counting each occurance.

 This example reads the file from stdin.

-File: `input.txt`
-
-```text
-Lorem ipsum dolor sit amet, 
+```bash
+echo "Lorem ipsum dolor sit amet, 
 consectetur adipiscing elit, 
 sed do eiusmod tempor incididunt 
 ut labore et dolore magna aliqua. 
 Ut enim ad minim veniam, 
 quis nostrud exercitation ullamco 
 laboris nisi ut aliquip ex ea 
-commodo consequat. 
-```
+commodo consequat." > input.txt

-```bash
 cat input.txt | skip 2 --token dolor
 ```

@ -94,8 +85,60 @@ Will output:
 Ut enim ad minim veniam, 
 quis nostrud exercitation ullamco 
 laboris nisi ut aliquip ex ea 
-commodo consequat. 
+commodo consequat.
 ```

 It matches the first `dolor` on line 1,
 and the second on line 4 as part of the word `dolore`.
+
+### Skip lines until a lines with tokens are seen
+
+Looks for a string within a line, only counting each matching line once.
+
+This example reads the file from stdin.
+
+```bash
+echo "Lorem ipsum dolor sit amet, 
+consectetur adipiscing elit, 
+sed do eiusmod tempor incididunt 
+ut labore et dolore magna aliqua. 
+Ut enim ad minim veniam, 
+quis nostrud exercitation ullamco 
+laboris nisi ut aliquip ex ea 
+commodo consequat." > input.txt
+
+cat input.txt | skip 4 --token m --ignore-extras
+```
+
+Will output:
+
+```text
+quis nostrud exercitation ullamco 
+laboris nisi ut aliquip ex ea 
+commodo consequat. 
+```
+
+Without `--ignore-extras`, it would have found the fourth `m` on line 3.
+
+```bash
+echo "Lorem ipsum dolor sit amet, 
+consectetur adipiscing elit, 
+sed do eiusmod tempor incididunt 
+ut labore et dolore magna aliqua. 
+Ut enim ad minim veniam, 
+quis nostrud exercitation ullamco 
+laboris nisi ut aliquip ex ea 
+commodo consequat." > input.txt
+
+cat input.txt | skip 4 --token m
+```
+
+Outputing:
+
+```text
+ut labore et dolore magna aliqua. 
+Ut enim ad minim veniam, 
+quis nostrud exercitation ullamco 
+laboris nisi ut aliquip ex ea 
+commodo consequat. 
+```
--- a/build.zig
+++ b/build.zig
@ -1,35 +0,0 @@
-const std = @import("std");
-const deps = @import("./deps.zig");
-
-pub fn build(b: *std.build.Builder) void {
-    // Standard target options allows the person running `zig build` to choose
-    // what target to build for. Here we do not override the defaults, which
-    // means any target is allowed, and the default is native. Other options
-    // for restricting supported target set are available.
-    const target = b.standardTargetOptions(.{});
-
-    // Standard release options allow the person running `zig build` to select
-    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
-    const mode = b.standardReleaseOptions();
-
-    const exe = b.addExecutable("skip", "src/main.zig");
-    exe.setTarget(target);
-    exe.setBuildMode(mode);
-    deps.addAllTo(exe);
-    exe.install();
-
-    const run_cmd = exe.run();
-    run_cmd.step.dependOn(b.getInstallStep());
-    if (b.args) |args| {
-        run_cmd.addArgs(args);
-    }
-
-    const run_step = b.step("run", "Run the app");
-    run_step.dependOn(&run_cmd.step);
-
-    const exe_tests = b.addTest("src/main.zig");
-    exe_tests.setBuildMode(mode);
-
-    const test_step = b.step("test", "Run unit tests");
-    test_step.dependOn(&exe_tests.step);
-}
--- a/15
+++ b/15
@ -0,0 +1,15 @@
+dist: target-release
+	if test ! -d dist ; then mkdir dist ; fi
+	cp target/release/skip dist/
+
+target-release: unittest inttest
+	cargo build --release
+
+inttest: target-debug
+	./test.sh
+
+unittest: target-debug
+	cargo test
+
+target-debug:
+	cargo build
--- a/renovate.json
+++ b/renovate.json
@ -0,0 +1,10 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": ["config:recommended"],
+  "packageRules": [
+    {
+      "matchManagers": ["cargo"],
+      "rangeStrategy": "replace"
+    }
+  ]
+}
--- a/src/lib.rs
+++ b/src/lib.rs
@ -0,0 +1,263 @@
+use clap::Parser;
+use std::fmt::Debug;
+use std::fs::File;
+use std::io::{BufRead, BufReader, Write};
+use std::path::PathBuf;
+
+pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
+
+/// Skip lines at the start of a file
+#[derive(Parser, Debug)]
+#[command(version)]
+pub struct Cli {
+    /// The number of lines (or tokens) to skip
+    lines: usize,
+    /// The file to read, or stdin if not given
+    pub file: Option<PathBuf>,
+    /// Skip until N lines matching this
+    #[arg(short, long, conflicts_with = "token")]
+    line: Option<String>,
+    /// Skip lines until N tokens found
+    #[arg(
+        short,
+        long,
+        conflicts_with = "line",
+        required_if_eq("ignore_extras", "true")
+    )]
+    token: Option<String>,
+    /// Only count the first token on each line
+    #[arg(short, long = "ignore-extras")]
+    ignore_extras: bool,
+}
+
+pub fn skip(cli: &Cli, writer: &mut impl Write) -> Result<()> {
+    let reader: Box<dyn BufRead> = match &cli.file {
+        Some(ref file) => {
+            let file = File::open(file)?;
+            Box::new(BufReader::new(file))
+        }
+        None => Box::new(BufReader::new(std::io::stdin())),
+    };
+    if let Some(line) = &cli.line {
+        skip_lines_matching(cli, reader, writer, line)
+    } else if let Some(ref token) = cli.token {
+        skip_tokens(cli, reader, writer, token)
+    } else {
+        skip_lines(cli, reader, writer)
+    }
+}
+
+// skip a number of lines
+fn skip_lines(cli: &Cli, reader: Box<dyn BufRead>, writer: &mut impl Write) -> Result<()> {
+    for (counter, current_line) in reader.lines().map_while(Option::Some).flatten().enumerate() {
+        if counter >= cli.lines {
+            writeln!(writer, "{}", current_line)?;
+        }
+    }
+    Ok(())
+}
+
+// skip until a number of matching lines seen
+fn skip_lines_matching(
+    cli: &Cli,
+    reader: Box<dyn BufRead>,
+    writer: &mut impl Write,
+    line: &str,
+) -> Result<()> {
+    let mut counter = 0usize;
+    for current_line in reader.lines().map_while(Option::Some).flatten() {
+        if counter >= cli.lines {
+            writeln!(writer, "{}", current_line)?;
+        }
+        if line == current_line {
+            counter += 1;
+        }
+    }
+    Ok(())
+}
+
+// skip until a number of tokens seen
+// may or may not count each occurance of token on a line - see cli.ignore_extras
+fn skip_tokens(
+    cli: &Cli,
+    reader: Box<dyn BufRead>,
+    writer: &mut impl Write,
+    token: &str,
+) -> Result<()> {
+    let mut counter = 0usize;
+
+    for current_line in reader.lines().map_while(Option::Some).flatten() {
+        if counter >= cli.lines {
+            writeln!(writer, "{}", current_line)?;
+        }
+        if current_line.contains(token) {
+            if cli.ignore_extras {
+                counter += 1;
+            } else {
+                let occurances = current_line.matches(&token).count();
+                counter += occurances;
+            }
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    #[test]
+    fn skip_one_line() -> Result<()> {
+        //given
+        let cli = Cli {
+            lines: 1,
+            file: Some(PathBuf::from("tests/two-lines.txt")),
+            line: None,
+            token: None,
+            ignore_extras: false,
+        };
+        let mut lines = Vec::new();
+
+        //when
+        skip(&cli, &mut lines)?;
+
+        //then
+        assert_eq!(String::from_utf8(lines)?, "line 2\n");
+        Ok(())
+    }
+
+    #[test]
+    fn skip_two_lines() -> Result<()> {
+        //given
+        let cli = Cli {
+            lines: 2,
+            file: Some(PathBuf::from("tests/four-lines.txt")),
+            line: None,
+            token: None,
+            ignore_extras: false,
+        };
+        let mut lines = Vec::new();
+
+        //when
+        skip(&cli, &mut lines)?;
+
+        //then
+        assert_eq!(String::from_utf8(lines)?, ["alpha", "gamma\n"].join("\n"));
+        Ok(())
+    }
+
+    #[test]
+    fn skip_two_matching_lines() -> Result<()> {
+        //given
+        let cli = Cli {
+            lines: 2,
+            file: Some(PathBuf::from("tests/four-lines.txt")),
+            line: Some(String::from("alpha")),
+            token: None,
+            ignore_extras: false,
+        };
+        let mut lines = Vec::new();
+
+        //when
+        skip(&cli, &mut lines)?;
+
+        //then
+        assert_eq!(String::from_utf8(lines)?, "gamma\n");
+        Ok(())
+    }
+
+    #[test]
+    fn skip_three_matching_tokens() -> Result<()> {
+        //given
+        let cli = Cli {
+            lines: 3,
+            file: Some(PathBuf::from("tests/poem.txt")),
+            line: None,
+            token: Some(String::from("one")),
+            ignore_extras: false,
+        };
+        let mut lines = Vec::new();
+
+        //when
+        skip(&cli, &mut lines)?;
+
+        //then
+        assert_eq!(
+            String::from_utf8(lines)?,
+            [
+                "Or help one fainting robin",
+                "Unto his nest again,",
+                "I shall not live in vain.\n"
+            ]
+            .join("\n")
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn skip_three_matching_tokens_include_extras() -> Result<()> {
+        //given
+        let cli = Cli {
+            lines: 4,
+            file: Some(PathBuf::from("tests/lorem.txt")),
+            line: None,
+            token: Some(String::from("or")),
+            ignore_extras: false,
+        };
+        let mut lines = Vec::new();
+
+        //when
+        skip(&cli, &mut lines)?;
+
+        //then
+        assert_eq!(
+            String::from_utf8(lines)?,
+            [
+                //Lorem ipsum dolor sit amet,        -- +2 = 2
+                //consectetur adipiscing elit,
+                //sed do eiusmod tempor incididunt   -- +1 = 3
+                //ut labore et dolore magna aliqua.  -- +2 = 5
+                "Ut enim ad minim veniam,",
+                "quis nostrud exercitation ullamco",
+                "laboris nisi ut aliquip ex ea",
+                "commodo consequat.\n"
+            ]
+            .join("\n")
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn skip_three_matching_tokens_ignore_extras() -> Result<()> {
+        //given
+        let cli = Cli {
+            lines: 4,
+            file: Some(PathBuf::from("tests/lorem.txt")),
+            line: None,
+            token: Some(String::from("or")),
+            ignore_extras: true,
+        };
+        let mut lines = Vec::new();
+
+        //when
+        skip(&cli, &mut lines)?;
+
+        //then
+        assert_eq!(
+            String::from_utf8(lines)?,
+            [
+                //Lorem ipsum dolor sit amet,        -- 1
+                //consectetur adipiscing elit,
+                //sed do eiusmod tempor incididunt   -- 2
+                //ut labore et dolore magna aliqua.  -- 3
+                //Ut enim ad minim veniam,
+                //quis nostrud exercitation ullamco
+                //laboris nisi ut aliquip ex ea      -- 4
+                "commodo consequat.\n"
+            ]
+            .join("\n")
+        );
+        Ok(())
+    }
+}
--- a/src/main.rs
+++ b/src/main.rs
@ -0,0 +1,8 @@
+use clap::Parser;
+use skip::{skip, Cli, Result};
+
+fn main() -> Result<()> {
+    let cli = Cli::parse();
+    let mut stdout = std::io::stdout();
+    skip(&cli, &mut stdout)
+}
--- a/src/main.zig
+++ b/src/main.zig
@ -1,321 +0,0 @@
-const std = @import("std");
-const builtin = @import("builtin");
-const os = builtin.os;
-const fmt = std.fmt;
-const mem = std.mem;
-const testing = std.testing;
-const io = std.io;
-const heap = std.heap;
-const fs = std.fs;
-const clap = @import("clap");
-
-const version = "0.1.0";
-
-// step 1: [x] read in a file from stdin and write out to stdout
-// step 2: [x] read in a named file in parameters and write out to stdout
-// step 3: [x] skip a number of lines
-// step 4: [ ] skip a number of matching lines
-// step 5: [ ] skip a number of tokens
-
-const maxLineLength = 4096;
-
-pub fn main() anyerror!void {
-    var buffer: [maxLineLength]u8 = undefined;
-    var fba = heap.FixedBufferAllocator.init(&buffer);
-    const allocator = fba.allocator();
-
-    const config: Config = parseArgs(allocator) catch |err| switch (err) {
-        error.EarlyExit => return,
-        error.FileNotFound => return,
-        error.BadArgs => return,
-        else => @panic("Unknown error"),
-    };
-    defer config.deinit();
-
-    const stdout = io.getStdOut();
-    if (config.file) |file| {
-        try dumpInput(config, file, stdout, allocator);
-    } else {
-        const stdin = io.getStdIn();
-        try dumpInput(config, stdin, stdout, allocator);
-    }
-}
-
-const errors = error {
-    EarlyExit,
-    FileNotFound,
-    BadArgs,
-};
-
-const Config = struct {
-    lines: u32,
-    file: ?fs.File,
-    line: ?[]const u8 = null,
-    token: ?[]const u8 = null,
-
-    pub fn deinit(self: @This()) void {
-        if (self.file) |f| {
-            f.close();
-        }
-    }
-};
-
-fn parseArgs(allocator: mem.Allocator) !Config {
-    const params = comptime [_]clap.Param(clap.Help) {
-        clap.parseParam("<N>               The number of lines to skip") catch unreachable,
-        clap.parseParam("[<FILE>]          The file to read or stdin if not given") catch unreachable,
-        clap.parseParam("-l, --line <STR>  Skip until N lines matching this") catch unreachable,
-        clap.parseParam("-t, --token <STR> Skip lines until N tokens found") catch unreachable,
-        clap.parseParam("-h, --help        Display this help and exit") catch unreachable,
-        clap.parseParam("-v, --version     Display the version") catch unreachable,
-    };
-    var diag = clap.Diagnostic{};
-    var args = clap.parse(clap.Help, &params, .{ .diagnostic = &diag }) catch |err| {
-        diag.report(io.getStdErr().writer(), err) catch {};
-        return err;
-    };
-    defer args.deinit();
-
-    if (args.flag("--version")) {
-        std.debug.print("skip version {s}\n", .{ version });
-        return error.EarlyExit;
-    }
-    if (args.flag("--help")) {
-        try io.getStdErr().writer().print("skip <N> [<FILE>] [-h|--help] [-v|--version]\n", .{});
-        try clap.help(io.getStdErr().writer(), &params);
-        return error.EarlyExit;
-    }
-
-    if (args.option("--line")) |_| {
-        if (args.option("--token")) |_| {
-            try io.getStdErr().writer().print("Error: only specify one of --line or --token, not both\n", .{});
-            return error.BadArgs;
-        }
-    }
-
-
-    var line: ?[]const u8 = null;
-    if (args.option("--line")) |match| {
-        line = try allocator.dupe(u8, match);
-    }
-
-    var token: ?[]const u8 = null;
-    if (args.option("--token")) |match| {
-        token = try allocator.dupe(u8, match);
-    }
-
-    var n: u32 = 0;
-    var file: ?fs.File = null;
-    if (args.positionals().len == 0) {
-        std.debug.print("Number of lines to skip not given. Try skip --help\n", .{});
-        return error.EarlyExit;
-    }
-    if (args.positionals().len >= 1) {
-        n = try fmt.parseInt(u32, args.positionals()[0], 10);
-    }
-    if (args.positionals().len >= 2) {
-        const filename = args.positionals()[1];
-        file = fs.cwd().openFile(filename, .{ .read = true, .write = false }) catch |err| switch (err) {
-            error.FileNotFound => {
-                try io.getStdErr().writer().print("Error: File not found: {s}\n",  .{ filename });
-                return err;
-            },
-            else => return err,
-        };
-    }
-    return Config {
-        .lines = n,
-        .file = file,
-        .line = line,
-        .token = token,
-    };
-}
-
-fn dumpInput(config: Config, in: fs.File, out: fs.File, allocator: mem.Allocator) !void {
-    const writer = out.writer();
-    const reader = in.reader();
-    var it: LineIterator = lineIterator(reader, allocator);
-    var c: usize = 0;
-    while (c < config.lines) {
-        const line = it.next();
-        if (config.line) |match| {
-            if (line) |memory| {
-                if (mem.eql(u8, match, memory)) {
-                    c += 1;
-                }
-            }
-        } else {
-            if (config.token) |token| {
-                if (line) |memory| {
-                    c += mem.count(u8, memory, token);
-                }
-            } else {
-                c += 1;
-            }
-        }
-        if (line) |memory| {
-            allocator.free(memory);
-        } else return;
-    }
-    try pumpIterator(&it, writer, allocator);
-}
-
-test "dumpInput skip 1 line" {
-    const file = try fs.cwd().openFile("src/test/two-lines.txt", .{ .read = true, .write = false });
-    defer file.close();
-
-    const tempFile = "zig-cache/test.txt";
-
-    const output = try fs.cwd().createFile(tempFile, .{});
-    defer output.close();
-
-    const config = Config{
-        .lines = 1,
-        .file = file,
-    };
-
-    try dumpInput(config, file, output, testing.allocator);
-
-    const result = try fs.cwd().openFile(tempFile, .{ .read = true });
-    defer result.close();
-
-    var rit = lineIterator(result.reader(), testing.allocator);
-
-    const line1 = rit.next().?;
-    defer testing.allocator.free(line1);
-    try testing.expectEqualStrings("line 2", line1);
-
-    const eof = rit.next();
-    try testing.expect(eof == null);
-}
-
-test "dumpInput skip 2 line 'alpha'" {
-    const file = try fs.cwd().openFile("src/test/four-lines.txt", .{ .read = true, .write = false });
-    defer file.close();
-
-    const tempFile = "zig-cache/test.txt";
-
-    const output = try fs.cwd().createFile(tempFile, .{});
-    defer output.close();
-
-    const config = Config{
-        .lines = 2,
-        .file = file,
-        .line = "alpha",
-    };
-
-    try dumpInput(config, file, output, testing.allocator);
-
-    const result = try fs.cwd().openFile(tempFile, .{ .read = true });
-    defer result.close();
-
-    var rit = lineIterator(result.reader(), testing.allocator);
-
-    const line1 = rit.next().?;
-    defer testing.allocator.free(line1);
-    try testing.expectEqualStrings("gamma", line1);
-
-    const eof = rit.next();
-    try testing.expect(eof == null);
-}
-
-fn pumpIterator(it: *LineIterator, writer: fs.File.Writer, allocator: mem.Allocator) !void {
-    while (it.next()) |line| {
-        defer allocator.free(line);
-        
-        try writer.print("{s}\n", .{ windowsSafe(line) });
-    }
-}
-
-test "pumpIterator" {
-    const file = try fs.cwd().openFile("src/test/two-lines.txt", .{ .read = true, .write = false });
-    defer file.close();
-
-    const tempFile = "zig-cache/test.txt";
-
-    const output = try fs.cwd().createFile(tempFile, .{});
-    defer output.close();
-
-    var reader = file.reader();
-    var it = lineIterator(reader, testing.allocator);
-
-    var writer = output.writer();
-
-    try pumpIterator(&it, writer, testing.allocator);
-
-    const result = try fs.cwd().openFile(tempFile, .{ .read = true });
-    defer result.close();
-
-    var rit = lineIterator(result.reader(), testing.allocator);
-
-    const line1 = rit.next().?;
-    defer testing.allocator.free(line1);
-    try testing.expectEqualStrings("line 1", line1);
-
-    const line2 = rit.next().?;
-    defer testing.allocator.free(line2);
-    try testing.expectEqualStrings("line 2", line2);
-    const eof = rit.next();
-
-    try testing.expect(eof == null);
-}
-
-const LineIterator = struct {
-    reader: io.BufferedReader(maxLineLength, fs.File.Reader),
-    delimiter: u8,
-    allocator: mem.Allocator,
-
-    const Self = @This();
-
-    /// Caller owns returned memory
-    pub fn next(self: *Self) ?[]u8 {
-        return self.reader.reader().readUntilDelimiterOrEofAlloc(self.allocator, self.delimiter, maxLineLength) catch null;
-    }
-};
-
-fn lineIterator(reader: fs.File.Reader, allocator: mem.Allocator) LineIterator {
-    return LineIterator {
-        .reader = io.bufferedReader(reader),
-        .delimiter = '\n',
-        .allocator = allocator
-    };
-}
-
-test "lineIterator returns lines in buffer" {
-    const file = try fs.cwd().openFile("src/test/two-lines.txt", .{ .read = true, .write = false });
-    defer file.close();
-
-    var reader = file.reader();
-    var it = lineIterator(reader, testing.allocator);
-
-    const line1 = it.next().?;
-    defer testing.allocator.free(line1);
-    try testing.expectEqualStrings("line 1", line1);
-
-    const line2 = it.next().?;
-    defer testing.allocator.free(line2);
-    try testing.expectEqualStrings("line 2", line2);
-    const eof = it.next();
-
-    try testing.expect(eof == null);
-}
-
-fn windowsSafe(line: []const u8) []const u8 {
-    // trim annoying windows-only carriage return character
-    if (os.tag == .windows) {
-        return mem.trimRight(u8, line, "\r");
-    }
-    return line;
-}
-
-test "windowsSafe strips carriage return on windows" {
-    const input = "line\n\r";
-    const result = windowsSafe(input);
-    if (os.tag == .windows) {
-        // strips the carriage return if windows
-        try testing.expectEqualSlices(u8, "line\n", result);
-    } else {
-        // doesn't change the line if not windows
-        try testing.expectEqualSlices(u8, input, result);
-    }
-}
--- a/test.sh
+++ b/test.sh
@ -2,27 +2,41 @@

 set -e

+echo "PWD: $PWD"
+ls -l
+ls -l target
+SKIP="./target/debug/skip"
+DIFF="diff -u --color"
+
+if test ! -x $SKIP; then
+  echo "File missing: $SKIP - try 'cargo build'"
+  exit 1
+fi
+
 echo "> skip a line when reading from stdin"
-INPUT=$(cat<<EOF
+INPUT=$(
+  cat <<EOF
 line 1
 line 2
 EOF
 )
-echo "line 2" > test.expect
-echo "$INPUT" | ./skip 1 > test.out
-diff --brief test.expect test.out
+echo "line 2" >test.expect
+echo "$INPUT" | $SKIP 1 >test.out
+$DIFF test.expect test.out
+rm test.expect test.out

 echo "> skip a line when reading from a file"
-cat<<EOF > test.in
+cat <<EOF >test.in
 line 1
 line 2
 EOF
-echo "line 2" > test.expect
-./skip 1 test.in > test.out
-diff --brief test.expect test.out
+echo "line 2" >test.expect
+$SKIP 1 test.in >test.out
+$DIFF test.expect test.out
+rm test.expect test.out

 echo "> skip until 2 matching lines seen"
-cat<<EOF > test.in
+cat <<EOF >test.in
 alpha
 beta
 alpha
@ -30,16 +44,17 @@ alpha
 gamma
 alpha
 EOF
-cat<<EOF > test.expect
+cat <<EOF >test.expect
 alpha
 gamma
 alpha
 EOF
-./skip 2 test.in --line alpha > test.out
-diff --brief test.expect test.out
+$SKIP 2 test.in --line alpha >test.out
+$DIFF test.expect test.out
+rm test.in test.expect test.out

 echo "> skip lines until 2 tokens seen"
-cat<<EOF > test.in
+cat <<EOF >test.in
 Lorem ipsum dolor sit amet, 
 consectetur adipiscing elit, 
 sed do eiusmod tempor incididunt 
@ -49,15 +64,72 @@ quis nostrud exercitation ullamco
 laboris nisi ut aliquip ex ea 
 commodo consequat. 
 EOF
-cat<<EOF > test.expect
+cat <<EOF >test.expect
 Ut enim ad minim veniam, 
 quis nostrud exercitation ullamco 
 laboris nisi ut aliquip ex ea 
 commodo consequat. 
 EOF
-./skip 2 test.in --token dolor > test.out
-diff --brief test.expect test.out
+$SKIP 2 test.in --token dolor >test.out
+$DIFF test.expect test.out
+rm test.in test.expect test.out

-rm test.in test.out test.expect
+echo "> handle unknown parameter with simple error message"
+cat <<EOF >test.expect.err
+error: unexpected argument '--foo' found
+
+  tip: to pass '--foo' as a value, use '-- --foo'
+
+Usage: skip [OPTIONS] <LINES> [FILE]
+
+For more information, try '--help'.
+EOF
+cat <<EOF >test.expect
+EOF
+touch test.out test.err
+$SKIP --foo >test.out 2>test.err || true
+$DIFF test.expect test.out
+$DIFF test.expect.err test.err
+rm test.expect test.out
+rm test.expect.err test.err
+
+echo "> handle ignore-extra when token is missing"
+cat <<EOF >test.expect.err
+error: the following required arguments were not provided:
+  --token <TOKEN>
+  <LINES>
+
+Usage: skip --ignore-extras --token <TOKEN> <LINES> [FILE]
+
+For more information, try '--help'.
+EOF
+cat <<EOF >test.expect
+EOF
+touch test.out test.err
+$SKIP --ignore-extras >test.out 2>test.err || true
+$DIFF test.expect test.out
+$DIFF test.expect.err test.err
+rm test.expect test.out
+rm test.expect.err test.err
+
+echo "> skip lines until 4 tokens seen - ignored extra tokens on same line"
+cat <<EOF >test.in
+Lorem ipsum dolor sit amet, 
+consectetur adipiscing elit, 
+sed do eiusmod tempor incididunt 
+ut labore et dolore magna aliqua. 
+Ut enim ad minim veniam, 
+quis nostrud exercitation ullamco 
+laboris nisi ut aliquip ex ea 
+commodo consequat. 
+EOF
+cat <<EOF >test.expect
+quis nostrud exercitation ullamco 
+laboris nisi ut aliquip ex ea 
+commodo consequat. 
+EOF
+$SKIP 4 test.in --token m --ignore-extras >test.out
+$DIFF test.expect test.out
+rm test.in test.expect test.out

 echo done
--- a/src/test/four-lines.txt
+++ b/src/test/four-lines.txt
--- a/tests/lorem.txt
+++ b/tests/lorem.txt
@ -0,0 +1,8 @@
+Lorem ipsum dolor sit amet,
+consectetur adipiscing elit,
+sed do eiusmod tempor incididunt
+ut labore et dolore magna aliqua.
+Ut enim ad minim veniam,
+quis nostrud exercitation ullamco
+laboris nisi ut aliquip ex ea
+commodo consequat.
--- a/tests/poem.txt
+++ b/tests/poem.txt
@ -0,0 +1,7 @@
+If I can stop one heart from breaking,
+I shall not live in vain;
+If I can ease one life the aching,
+Or cool one pain,
+Or help one fainting robin
+Unto his nest again,
+I shall not live in vain.
--- a/src/test/two-lines.txt
+++ b/src/test/two-lines.txt
--- a/zig.mod
+++ b/zig.mod
@ -1,6 +0,0 @@
-id: va9657y7sc352r94jivh9b17lnaffyrou0dlu3x45n5ifm2q
-name: skip
-license: MIT
-description: skip part of a file 
-dev_dependencies:
-    - src: git https://github.com/Hejsil/zig-clap
--- a/zigmod.lock
+++ b/zigmod.lock
@ -1,2 +0,0 @@
-2
-git https://github.com/Hejsil/zig-clap commit-802a04a854e65254b0632d9785b2b0f6154686b8