Revert "perf: buffer-at-a-time search for literal patterns"

fuzz: add differential fuzzer against GNU grep

.github/workflows/GnuTests.yml

@@ -9,6 +9,9 @@ on:
     branches:
       - '*'
 
+permissions:
+  contents: write # Publish grep instead of discarding
+
 # End the current execution if there is a new changeset in the PR.
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -47,7 +50,21 @@ jobs:
       shell: bash
       run: |
         cd 'grep'
-        cargo build --release
+        cargo build --release --config=profile.release.strip=true
+        tar -C target/release -cf - grep | zstd -19 -o ../grep-x86_64-unknown-linux-gnu.tar.zst
+    - name: Publish latest commit
+      uses: softprops/action-gh-release@v3
+      if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+      with:
+        tag_name: latest-commit
+        body: |
+          commit: ${{ github.sha }}
+        draft: false
+        prerelease: true
+        files: |
+          grep-x86_64-unknown-linux-gnu.tar.zst
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
     - name: Run GNU grep testsuite
       shell: bash

README.md

@@ -11,6 +11,23 @@
 A Rust implementation of [GNU Grep](https://www.gnu.org/software/grep/).
 This project is an initial release and may contain bugs.
 
+## Install
+
+```shell
+cargo install uu_grep
+```
+
+## 🚀 Try it online
+
+You can try `grep` directly in your browser on the [uutils playground](https://uutils.github.io/playground/).
+Arguments (and a full command) can be passed through the URL via the `cmd` query parameter, for example:
+
+```shell
+printf '🚀 rocket\n🛰️ satellite\n🌙 moon\n⭐ star\n' | grep 🌙
+```
+
+[Run it in the playground](https://uutils.github.io/playground/?cmd=printf%20%27%F0%9F%9A%80%20rocket%5Cn%F0%9F%9B%B0%EF%B8%8F%20satellite%5Cn%F0%9F%8C%99%20moon%5Cn%E2%AD%90%20star%5Cn%27%20%7C%20grep%20%F0%9F%8C%99)
+
 ## Building
 
 Download Rust at: https://rustup.rs/

src/lib.rs

@@ -255,6 +255,14 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         ));
     }
 
+    // GNU grep's PCRE backend (-P) supports only a single pattern.
+    if perl_regexp && patterns.len() > 1 {
+        return Err(USimpleError::new(
+            2,
+            "the -P option only supports a single pattern".to_string(),
+        ));
+    }
+
     // Decoded options into enums
     let regex_mode = if fixed_strings {
         RegexMode::Fixed
@@ -707,14 +715,16 @@ pub fn uu_app() -> Command {
                 .short('L')
                 .long("files-without-match")
                 .help("print only names of FILEs with no selected lines")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with("files_with_matches"),
         )
         .arg(
             Arg::new("files_with_matches")
                 .short('l')
                 .long("files-with-matches")
                 .help("print only names of FILEs with selected lines")
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .overrides_with("files_without_match"),
         )
         .arg(
             Arg::new("count")

src/matcher.rs

@@ -28,13 +28,10 @@ impl<'a> Matcher<'a> {
     /// Decide whether `line` matches and return the positions to highlight.
     pub fn match_line(&self, line: &[u8]) -> Option<Vec<(usize, usize)>> {
         let mut any_seen = false;
+        let mut any_selected = false;
         let positions: Vec<_> = MatchIter::new(&self.patterns, line)
             .filter(|&(start, end)| {
                 any_seen = true;
-                // Drop zero-length matches from the output.
-                if start == end {
-                    return false;
-                }
                 // Drop matches that don't span the whole line if `-x` was requested.
                 if self.config.line_regexp && !(start == 0 && end == line.len()) {
                     return false;
@@ -43,13 +40,19 @@ impl<'a> Matcher<'a> {
                 if self.config.word_regexp && !Self::is_word_match(line, start, end) {
                     return false;
                 }
+                any_selected = true;
+                // Drop zero-length matches from the output.
+                if start == end {
+                    return false;
+                }
                 true
             })
             .collect();
 
         let raw_matched = if self.config.line_regexp || self.config.word_regexp {
-            // -w / -x are authoritative once positions are filtered.
-            !positions.is_empty()
+            // -w / -x are authoritative once matches are filtered. Zero-length
+            // matches can select a line even though there is no span to output.
+            any_selected
         } else {
             any_seen
         };
@@ -174,7 +177,7 @@ struct Cursor<'a> {
 
 impl Cursor<'_> {
     fn refill(&mut self) {
-        if self.offset >= self.line.len() {
+        if self.offset > self.line.len() {
             self.pending = None;
             return;
         }

src/output.rs

@@ -71,6 +71,7 @@ impl<'a> OutputWriter<'a> {
                 view.line_number,
                 view.byte_offset + start as u64,
                 b':',
+                false,
             )?;
 
             self.write_colored_bytes(
@@ -90,6 +91,7 @@ impl<'a> OutputWriter<'a> {
             view.line_number,
             view.byte_offset,
             if view.is_match { b':' } else { b'-' },
+            view.line.is_empty(),
         )?;
 
         let mut last_end = 0;
@@ -125,6 +127,7 @@ impl<'a> OutputWriter<'a> {
         line_number: u64,
         byte_offset: u64,
         sep_char: u8,
+        content_empty: bool,
     ) -> io::Result<()> {
         if self.config.show_filename {
             self.write_colored_fmt(
@@ -155,7 +158,10 @@ impl<'a> OutputWriter<'a> {
             self.write_separator(sep_char)?;
         }
 
+        // GNU grep aligns content with a tab under -T, but only when there is
+        // content to align: an empty line keeps just its prefix (no tab).
         if self.config.initial_tab
+            && !content_empty
             && (self.config.line_number || self.config.byte_offset || self.config.show_filename)
         {
             self.out.write_all(b"\t")?;

src/searcher.rs

@@ -283,7 +283,9 @@ impl<'a> Searcher<'a> {
 
             if let Some(positions) = self.session_match_line(line) {
                 // TODO: GNU grep respects LANG. Here, I'm always checking for valid UTF-8.
-                if !self.session_mark_binary_if(|| std::str::from_utf8(line).is_err()) {
+                if self.config.binary_mode != BinaryMode::WithoutMatch
+                    && !self.session_mark_binary_if(|| std::str::from_utf8(line).is_err())
+                {
                     return Ok(false);
                 }
 

tests/test_grep.rs

@@ -126,6 +126,24 @@ fn ere_invalid_pattern_is_error() {
         .stderr_contains("invalid pattern");
 }
 
+#[test]
+fn initial_tab_skips_empty_lines() {
+    // -T aligns content with a tab, but GNU omits the tab for an empty line
+    // (a whitespace-only line still gets one). -H forces the filename prefix
+    // on, so the tab is exercised.
+    let (s, mut c) = ucmd();
+    s.fixtures.write("in", "x\n\n");
+    c.args(&["-T", "-H", "^", "in"])
+        .succeeds()
+        .stdout_is("in:\tx\nin:\n");
+
+    let (s, mut c) = ucmd();
+    s.fixtures.write("in", "x\n \n");
+    c.args(&["-T", "-H", "^", "in"])
+        .succeeds()
+        .stdout_is("in:\tx\nin:\t \n");
+}
+
 #[test]
 fn fixed_string_is_literal() {
     // Metacharacters are not interpreted.
@@ -170,6 +188,34 @@ fn pcre_features() {
         .stdout_only("42\n7\n");
 }
 
+#[test]
+fn perl_regexp_rejects_multiple_patterns() {
+    // GNU grep's PCRE backend (-P) only supports a single pattern.
+    // Multiple -e patterns must produce exit 2 and the canonical error message.
+    // See: https://github.com/uutils/grep/issues/34
+
+    // Two separate -e flags.
+    let (_s, mut c) = ucmd();
+    c.args(&["-P", "-e", "foo", "-e", "bar"])
+        .pipe_in("foo\nbar\n")
+        .fails_with_code(2)
+        .stderr_contains("the -P option only supports a single pattern");
+
+    // A newline inside the pattern string is split into multiple patterns.
+    let (_s, mut c) = ucmd();
+    c.args(&["-P", "-e", "foo\nbar"])
+        .pipe_in("foo\nbar\n")
+        .fails_with_code(2)
+        .stderr_contains("the -P option only supports a single pattern");
+
+    // A single pattern with -P must still work normally.
+    let (_s, mut c) = ucmd();
+    c.args(&["-P", "-e", r"\d+"])
+        .pipe_in("abc\n42\n")
+        .succeeds()
+        .stdout_only("42\n");
+}
+
 #[test]
 fn posix_character_classes() {
     let (_s, mut c) = ucmd();
@@ -251,6 +297,12 @@ fn word_regexp() {
         .pipe_in("foo bar\nfoobar\n")
         .succeeds()
         .stdout_only("foo bar\n");
+
+    let (_s, mut c) = ucmd();
+    c.args(&["-w", "$"])
+        .pipe_in("abc\n\nx\n")
+        .succeeds()
+        .stdout_only("\n");
 }
 
 #[test]
@@ -260,6 +312,12 @@ fn line_regexp() {
         .pipe_in("foo bar\nfoo bar!\nx foo bar\n")
         .succeeds()
         .stdout_only("foo bar\n");
+
+    let (_s, mut c) = ucmd();
+    c.args(&["-x", "$"])
+        .pipe_in("abc\n\nx\n")
+        .succeeds()
+        .stdout_only("\n");
 }
 
 #[test]
@@ -460,6 +518,25 @@ fn files_with_and_without_matches() {
         .stdout_only("many\n");
 }
 
+#[test]
+fn files_with_and_without_matches_mutually_exclusive() {
+    // Test that -l and -L are mutually exclusive with last-one-wins semantics
+    let (scene, mut c) = ucmd();
+    scene.fixtures.write("file", "match\n");
+
+    // -l -L: last flag (-L) wins, so no output (file has match, -L excludes it)
+    c.args(&["-l", "-L", "match", "file"])
+        .succeeds()
+        .stdout_only("");
+
+    // -L -l: last flag (-l) wins, so filename is printed
+    let (scene, mut c) = ucmd();
+    scene.fixtures.write("file", "match\n");
+    c.args(&["-L", "-l", "match", "file"])
+        .succeeds()
+        .stdout_only("file\n");
+}
+
 #[test]
 fn count_combined_with_listing_flags() {
     let (scene, _) = ucmd();
@@ -862,6 +939,7 @@ fn binary_files_text_forces_text_mode() {
 fn binary_files_without_match_skips() {
     let (scene, _) = ucmd();
     scene.fixtures.write_bytes("b", b"hit\0more\n");
+    scene.fixtures.write_bytes("invalid", b"a\x9db\n");
 
     let mut c = scene.cmd(env!("CARGO_BIN_EXE_grep"));
     c.args(&["-I", "hit", "b"]).fails_with_code(1).no_output();
@@ -870,6 +948,18 @@ fn binary_files_without_match_skips() {
     c.args(&["--binary-files=without-match", "hit", "b"])
         .fails_with_code(1)
         .no_output();
+
+    let mut c = scene.cmd(env!("CARGO_BIN_EXE_grep"));
+    c.args(&["-I", "a", "invalid"])
+        .succeeds()
+        .stdout_is_bytes(b"a\x9db\n")
+        .no_stderr();
+
+    let mut c = scene.cmd(env!("CARGO_BIN_EXE_grep"));
+    c.args(&["--binary-files=without-match", "a", "invalid"])
+        .succeeds()
+        .stdout_is_bytes(b"a\x9db\n")
+        .no_stderr();
 }
 
 fn build_tree(scene: &TestScenario) {