diff --git a/src/main.rs b/src/main.rs
index 7343cb7..ae32146 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,20 +13,14 @@ pub mod tool;
 pub mod util;
 
 // enumerate files with a spinner (count size)
-// warn if links and follow
 // trim everything
 // parallelism
 // input from stdin?
-// * ** greed
-// fix and document "**.flac", "**/*.flac"
-// tests
 // show progress
-// bash before and after
 // capture/print stdout/stderr
 // workdir vs root?
 //
 // Tools:
-// - *** bash
 // - * list
 // - *** rename
 // - ** typst
@@ -116,11 +110,13 @@ fn main_inner() -> Result<ExitCode> {
 	// MARK: rules
 	//
 
-	let rules = manifest
-		.rules
-		.iter()
-		.map(|rule| (rule.regex(), rule.tasks))
-		.collect::<Vec<_>>();
+	let rules = {
+		let mut rules = Vec::new();
+		for rule in &manifest.rules {
+			rules.push((rule.regex()?, rule.tasks));
+		}
+		rules
+	};
 
 	let source_path = std::path::absolute(&work_dir)?;
 	let walker = WalkDir::new(&source_path).follow_links(manifest.config.follow_links);
diff --git a/src/manifest.rs b/src/manifest.rs
index 7202c00..a49d16f 100644
--- a/src/manifest.rs
+++ b/src/manifest.rs
@@ -1,8 +1,9 @@
-use anyhow::Result;
+use anyhow::{Result, bail};
 use indexmap::IndexMap;
 use regex::Regex;
 use serde::Deserialize;
 use std::path::{Path, PathBuf};
+use tracing::warn;
 
 use crate::tool::ToolConfig;
 
@@ -146,24 +147,155 @@ pub struct FlatPickRule {
 	pub tasks: Vec<String>,
 }
 
+#[derive(Debug)]
+enum RegexSegment {
+	/// A single segment
+	Single(String),
+
+	/// An optional doublestar segment
+	DoubleStar,
+}
+
+impl RegexSegment {
+	/// Returns the regex pattern of this part,
+	/// prefixed with a /.
+	fn to_regex_part(&self, prev: Option<&Self>, next: Option<&Self>) -> String {
+		match (prev, self, next) {
+			// Consecutive single segments need a trailing slash
+			(_, Self::Single(x), Some(Self::Single(_))) => format!("{x}[/]"),
+
+			// Terminal single segments don't need a trailing slash
+			(_, Self::Single(x), None) => x.to_owned(),
+
+			// Neighboring doublestar is always responsible for slashes
+			(_, Self::Single(x), Some(Self::DoubleStar)) => x.to_owned(),
+
+			// [^/]+ is a "segment" (a block of non-slash chars)
+			// The "base" doublestar pattern is a segment
+			// followed by zero or more segments prefixed by a slash.
+			//
+			// No additional slashes
+			(None, Self::DoubleStar, None) => "((?:[^/]+(?:[/][^/]+)*)?)".into(),
+
+			// Doublestars cannot be neighbors
+			(_, Self::DoubleStar, Some(Self::DoubleStar))
+			| (Some(Self::DoubleStar), Self::DoubleStar, _) => {
+				unreachable!("consecutive doublestars must be reduced")
+			}
+
+			// Leading slash
+			(Some(Self::Single(_)), Self::DoubleStar, None) => {
+				"((?:[/][^/]+(?:[/][^/]+)*)?)".into()
+			}
+
+			// Trailing slash
+			(None, Self::DoubleStar, Some(Self::Single(_))) => {
+				"((?:[^/]+(?:[/][^/]+)*[/])?)".into()
+			}
+
+			// Leading and trailing slash.
+			// Also, replace self with a [/] when empty.
+			(Some(Self::Single(_)), Self::DoubleStar, Some(Self::Single(_))) => {
+				"((?:[/][^/]+(?:[/][^/]+)*[/])|[/])".into()
+			}
+		}
+	}
+}
+
 impl FlatPickRule {
-	pub fn regex(&self) -> Regex {
+	pub fn regex(&self) -> Result<Regex> {
+		// Flatten pattern
+		// Double slashes are handled later
+		let pattern = self.patterns.join("/");
+
+		if pattern.ends_with("/") {
+			warn!("Pattern `{pattern}` has a trailing slash which will be ignored")
+		}
+
+		if pattern.starts_with("/") {
+			warn!("Pattern `{pattern}` has a leading slash which will be ignored")
+		}
+
+		// Split on slashes or stars
+		// This is a lot like .split("/"), but handles
+		// the edge case where ** is not delimited by slashes
+		// (`root**test` is equivalent to `root/**/test`)
+		let segments = {
+			#[expect(clippy::unwrap_used)]
+			let re = Regex::new("[*]{2,}|[/]").unwrap();
+			let split = re.find_iter(&pattern);
+
+			let bounds = split
+				.into_iter()
+				.flat_map(|x| {
+					let r = x.range();
+					let a = r.start;
+					let b = r.end;
+					[a, b]
+				})
+				.chain([pattern.len()])
+				.collect::<Vec<_>>();
+
+			let mut parts = Vec::new();
+			let mut last = 0;
+			for next in bounds {
+				let seg = &pattern[last..next];
+				// Consecutive slashes are identical to a single slash
+				if seg != "/" && !seg.is_empty() {
+					parts.push(seg);
+				}
+				last = next;
+			}
+
+			parts
+		};
+
+		let mut rebuilt_segments = Vec::new();
+		let mut last_was_doublestar = false;
+		for segment in segments {
+			// This is a wilcard regex
+			// (**, ***, etc)
+			if segment.len() > 1 && segment.chars().all(|x| x == '*') {
+				match segment {
+					"**" => {
+						// Consecutive doublestars are meaningless
+						if !last_was_doublestar {
+							rebuilt_segments.push(RegexSegment::DoubleStar);
+						}
+						last_was_doublestar = true;
+					}
+					_ => bail!("Invalid wildcard `{segment}`"),
+				}
+				continue;
+			}
+			last_was_doublestar = false;
+
+			let parts = segment.split("*").collect::<Vec<_>>();
+
+			let mut rebuilt = String::new();
+			for (i, part) in parts.into_iter().enumerate() {
+				if i != 0 {
+					rebuilt.push_str("([^/]*)")
+				}
+
+				rebuilt.push_str(&regex::escape(part));
+			}
+
+			rebuilt_segments.push(RegexSegment::Single(rebuilt));
+		}
+
+		let mut re_built = String::new();
+		let mut prev = None;
+		for (i, seg) in rebuilt_segments.iter().enumerate() {
+			let next = rebuilt_segments.get(i + 1);
+			re_built.push_str(&seg.to_regex_part(prev, next));
+			prev = Some(seg);
+		}
+
+		let re_built = format!("^{re_built}$");
 		// This regex should always be valid
 		#[expect(clippy::unwrap_used)]
-		Regex::new(
-			&self
-				.patterns
-				.join("/")
-				.split("/")
-				.map(|x| match x {
-					"**" => "((:?[^/]+)*)".to_owned(),
-					"*" => "([^/]+)".to_owned(),
-					x => regex::escape(x),
-				})
-				.collect::<Vec<_>>()
-				.join("/"),
-		)
-		.unwrap()
+		Ok(Regex::new(&re_built).unwrap())
 	}
 }
 
@@ -363,4 +495,287 @@ mod tests {
 		let result = toml::from_str::<TestManifest>(toml_str);
 		assert!(result.is_err());
 	}
+
+	#[test]
+	fn pattern_simple() {
+		let rule = FlatPickRule {
+			patterns: vec!["file.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("file.txt"));
+		assert!(!regex.is_match("other.txt"));
+		assert!(!regex.is_match("path/file.txt"));
+	}
+
+	#[test]
+	fn pattern_with_path() {
+		let rule = FlatPickRule {
+			patterns: vec!["dir".to_string(), "file.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("dir/file.txt"));
+		assert!(!regex.is_match("file.txt"));
+		assert!(!regex.is_match("other/file.txt"));
+	}
+
+	#[test]
+	fn pattern_wildcard_simple() {
+		let rule = FlatPickRule {
+			patterns: vec!["*.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("file.txt"));
+		assert!(regex.is_match("other.txt"));
+		assert!(!regex.is_match("file.jpg"));
+		assert!(!regex.is_match("nested/file.txt"));
+	}
+
+	#[test]
+	fn pattern_doublestar() {
+		let rule = FlatPickRule {
+			patterns: vec!["**".to_string(), "*.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("file.txt"));
+		assert!(regex.is_match("dir/file.txt"));
+		assert!(regex.is_match("dir/subdir/file.txt"));
+		assert!(!regex.is_match("file.jpg"));
+		assert!(!regex.is_match("dir/file.jpg"));
+	}
+
+	#[test]
+	fn pattern_doublestar_consecutive() {
+		let rule = FlatPickRule {
+			patterns: vec![
+				"**".to_string(),
+				"**".to_string(),
+				"**".to_string(),
+				"*.txt".to_string(),
+			],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("file.txt"));
+		assert!(regex.is_match("dir/file.txt"));
+		assert!(regex.is_match("dir/subdir/file.txt"));
+		assert!(!regex.is_match("file.jpg"));
+		assert!(!regex.is_match("dir/file.jpg"));
+	}
+
+	#[test]
+	fn pattern_wildcard_double_slash() {
+		let rule = FlatPickRule {
+			patterns: vec!["**/*.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("file.txt"));
+		assert!(regex.is_match("dir/file.txt"));
+		assert!(regex.is_match("dir/subdir/file.txt"));
+		assert!(!regex.is_match("file.jpg"));
+		assert!(!regex.is_match("dir/file.jpg"));
+	}
+
+	#[test]
+	fn pattern_single_dual() {
+		let rule = FlatPickRule {
+			patterns: vec!["**/*a*".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("fileafile"));
+		assert!(regex.is_match("dir/fileafile"));
+		assert!(regex.is_match("filea"));
+		assert!(regex.is_match("dir/filea"));
+		assert!(regex.is_match("afile"));
+		assert!(regex.is_match("dir/afile"));
+		assert!(!regex.is_match("noletter"));
+		assert!(!regex.is_match("dir/noletter"));
+	}
+
+	#[test]
+	fn pattern_single_end() {
+		let rule = FlatPickRule {
+			patterns: vec!["**/*".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("file"));
+		assert!(regex.is_match("dir/file"));
+	}
+
+	#[test]
+	fn pattern_double_end() {
+		let rule = FlatPickRule {
+			patterns: vec!["root/**".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("root/file"));
+		assert!(!regex.is_match("dir/file"));
+	}
+
+	#[test]
+	fn pattern_double_start() {
+		let rule = FlatPickRule {
+			patterns: vec!["**/dir".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("dir"));
+		assert!(regex.is_match("a/b/dir"));
+		assert!(!regex.is_match("dir/file"));
+	}
+
+	#[test]
+	fn pattern_double_adjacent_before() {
+		let rule = FlatPickRule {
+			// equivalent to root/**/test
+			patterns: vec!["root/**test".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("root/test"));
+		assert!(regex.is_match("root/a/test"));
+		assert!(regex.is_match("root/a/b/c/test"));
+		assert!(!regex.is_match("root/file"));
+		assert!(!regex.is_match("root/xxtest"));
+	}
+
+	#[test]
+	fn pattern_double_adjacent_after() {
+		let rule = FlatPickRule {
+			// equivalent to root/test/**
+			patterns: vec!["root/test**".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("root/test"));
+		assert!(regex.is_match("root/test/a"));
+		assert!(regex.is_match("root/test/a/b/c"));
+		assert!(!regex.is_match("root/testxx"));
+		assert!(!regex.is_match("root/file"));
+	}
+
+	#[test]
+	fn pattern_bad_any_extension() {
+		let rule = FlatPickRule {
+			// equivalent to root/test/**
+			patterns: vec!["**.flac".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("root/.flac"));
+		assert!(regex.is_match("root/a/.flac"));
+		assert!(!regex.is_match("root/test.flac"));
+		assert!(!regex.is_match("test.flac"));
+		assert!(!regex.is_match("root/test/a/b/c.flac"));
+		assert!(!regex.is_match("root/testflac"));
+		assert!(!regex.is_match("test.mp3"));
+	}
+
+	#[test]
+	fn pattern_good_any_extension() {
+		let rule = FlatPickRule {
+			// equivalent to root/test/**
+			patterns: vec!["**/*.flac".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("root/.flac"));
+		assert!(regex.is_match("root/a/.flac"));
+		assert!(regex.is_match("root/test.flac"));
+		assert!(regex.is_match("test.flac"));
+		assert!(regex.is_match("root/test/a/b/c.flac"));
+		assert!(!regex.is_match("root/testflac"));
+		assert!(!regex.is_match("test.mp3"));
+	}
+
+	#[test]
+	fn pattern_double_adjacent_between() {
+		let rule = FlatPickRule {
+			// equivalent to root/test/**/file
+			patterns: vec!["root/test**file".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("root/test/file"));
+		assert!(regex.is_match("root/test/a/b/c/file"));
+		assert!(!regex.is_match("root/test"));
+		assert!(!regex.is_match("root/file"));
+		assert!(!regex.is_match("root/testfile"));
+		assert!(!regex.is_match("root/testxxfile"));
+	}
+
+	#[test]
+	fn pattern_double_slashes() {
+		let rule = FlatPickRule {
+			patterns: vec!["dir//file.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("dir/file.txt"));
+		assert!(!regex.is_match("dirfile.txt"));
+		assert!(!regex.is_match("dir/other.txt"));
+	}
+
+	#[test]
+	fn pattern_double_slash() {
+		let rule = FlatPickRule {
+			patterns: vec!["a///b////c.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("a/b/c.txt"));
+		assert!(!regex.is_match("abc.txt"));
+		assert!(!regex.is_match("a/b/d.txt"));
+	}
+
+	#[test]
+	fn pattern_double_slash_wildcards() {
+		let rule = FlatPickRule {
+			patterns: vec!["**///*.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("dir/file.txt"));
+		assert!(regex.is_match("dir/subdir/file.txt"));
+		assert!(!regex.is_match("file.jpg"));
+	}
+
+	#[test]
+	fn pattern_slashes_around_wildcards() {
+		let rule = FlatPickRule {
+			patterns: vec!["dir//**//*.txt".to_string()],
+			tasks: vec!["copy".to_string()],
+		};
+
+		let regex = rule.regex().unwrap();
+		assert!(regex.is_match("dir/subdir/file.txt"));
+		assert!(regex.is_match("dir/sub1/sub2/file.txt"));
+		assert!(!regex.is_match("other/sub/file.txt"));
+		assert!(!regex.is_match("dir/file.jpg"));
+	}
 }
diff --git a/src/tool/bash.rs b/src/tool/bash.rs
index a1f76ca..9858392 100644
--- a/src/tool/bash.rs
+++ b/src/tool/bash.rs
@@ -2,7 +2,7 @@ use anyhow::{Context, Result};
 use serde::Deserialize;
 use std::io::Write;
 use std::{collections::HashMap, path::Path};
-use tracing::{error, trace, warn};
+use tracing::{debug, error, trace, warn};
 
 use crate::manifest::PickConfig;
 
@@ -31,7 +31,7 @@ impl PickTool for ToolBash {
 			}
 
 			Some(script) => {
-				trace!("Running `before` script");
+				debug!("Running `before` script");
 				let mut temp_file =
 					tempfile::NamedTempFile::new().context("while creating temporary script")?;
 				writeln!(temp_file, "{}", script).context("while creating temporary script")?;
@@ -79,7 +79,7 @@ impl PickTool for ToolBash {
 			}
 
 			Some(script) => {
-				trace!("Running `after` script");
+				debug!("Running `after` script");
 				let mut temp_file =
 					tempfile::NamedTempFile::new().context("while creating temporary script")?;
 				writeln!(temp_file, "{}", script).context("while creating temporary script")?;
diff --git a/test.toml b/test.toml
index 3c41598..abd4179 100644
--- a/test.toml
+++ b/test.toml
@@ -53,7 +53,7 @@ ffmpeg \
 # All rules are matched against the FULL PATH of files.
 # Directories are ignored.
 [[rules]]
-"**" = "test"
+"**.flac" = "test"
 
 [[rules]]
 "**" = ""