More progress. With coloring!

Cargo.toml

@@ -23,6 +23,8 @@ crossbeam = "0.2"
 docopt = "0.6"
 env_logger = "0.3"
 grep = { version = "0.1", path = "grep" }
+lazy_static = "0.2"
+libc = "0.2"
 log = "0.3"
 memchr = "0.1"
 memmap = "0.2"
@@ -31,15 +33,19 @@ parking_lot = "0.3"
 regex = { version = "0.1", path = "/home/andrew/rust/regex" }
 regex-syntax = { version = "0.3.1", path = "/home/andrew/rust/regex/regex-syntax" }
 rustc-serialize = "0.3"
+term = { version = "0.4", path = "/home/andrew/clones/term" }
 thread_local = "0.2"
 walkdir = "0.1"
 
+[target.'cfg(windows)'.dependencies]
+kernel32-sys = "0.2"
+winapi = "0.2"
+
 [features]
 simd-accel = ["regex/simd-accel"]
 
 [dev-dependencies]
 glob = "0.2"
-lazy_static = "0.2"
 
 [profile.release]
 debug = true

src/args.rs

@@ -16,6 +16,7 @@ use ignore::Ignore;
 use out::Out;
 use printer::Printer;
 use search::{InputBuffer, Searcher};
+use sys;
 use types::{FileTypeDef, Types, TypesBuilder};
 use walk;
 
@@ -37,6 +38,9 @@ xrep is like the silver searcher and grep, but faster than both.
 Common options:
     -a, --text                 Search binary files as if they were text.
     -c, --count                Only show count of line matches for each file.
+    --color WHEN               Whether to use coloring in match.
+                               Valid values are never, always or auto.
+                               [default: auto]
     -g, --glob GLOB ...        Include or exclude files for searching that
                                match the given glob. This always overrides any
                                other ignore logic. Multiple glob flags may be
@@ -44,8 +48,13 @@ Common options:
                                Precede a glob with a '!' to exclude it.
     -h, --help                 Show this usage message.
     -i, --ignore-case          Case insensitive search.
-    -n, --line-number          Show line numbers (1-based).
+    -n, --line-number          Show line numbers (1-based). This is enabled
+                               by default at a tty.
+    -N, --no-line-number       Suppress line numbers.
     -q, --quiet                Do not print anything to stdout.
+    -r, --replace ARG          Replace every match with the string given.
+                               Capture group indices (e.g., $5) and names
+                               (e.g., $foo) are supported.
     -t, --type TYPE ...        Only search files matching TYPE. Multiple type
                                flags may be provided. Use the --type-list flag
                                to list all available types.
@@ -80,6 +89,13 @@ Less common options:
         Prefix each match with the file name that contains it. This is the
         default when more than one file is searched.
 
+    --heading
+        Show the file name above clusters of matches from each file.
+        This is the default mode at a tty.
+
+    --no-heading
+        Don't show any file name heading.
+
     --hidden
         Search hidden directories and files.
 
@@ -93,10 +109,16 @@ Less common options:
     --no-ignore
         Don't respect ignore files (.gitignore, .xrepignore, etc.)
 
+    --no-ignore-parent
+        Don't respect ignore files in parent directories.
+
+    -p, --pretty
+        Alias for --color=always --heading -n.
+
     -Q, --literal
         Treat the pattern as a literal string instead of a regular expression.
 
-    --threads ARG
+    -j, --threads ARG
         The number of threads to use. Defaults to the number of logical CPUs
         (capped at 6). [default: 0]
 
@@ -123,6 +145,7 @@ pub struct RawArgs {
     arg_path: Vec<String>,
     flag_after_context: usize,
     flag_before_context: usize,
+    flag_color: String,
     flag_context: usize,
     flag_context_separator: String,
     flag_count: bool,
@@ -130,14 +153,20 @@ pub struct RawArgs {
     flag_files: bool,
     flag_follow: bool,
     flag_glob: Vec<String>,
+    flag_heading: bool,
     flag_hidden: bool,
     flag_ignore_case: bool,
     flag_invert_match: bool,
     flag_line_number: bool,
     flag_line_terminator: String,
     flag_literal: bool,
+    flag_no_heading: bool,
     flag_no_ignore: bool,
+    flag_no_ignore_parent: bool,
+    flag_no_line_number: bool,
+    flag_pretty: bool,
     flag_quiet: bool,
+    flag_replace: Option<String>,
     flag_text: bool,
     flag_threads: usize,
     flag_type: Vec<String>,
@@ -156,18 +185,22 @@ pub struct Args {
     paths: Vec<PathBuf>,
     after_context: usize,
     before_context: usize,
+    color: bool,
     context_separator: Vec<u8>,
     count: bool,
     eol: u8,
     files: bool,
     follow: bool,
     glob_overrides: Option<Gitignore>,
+    heading: bool,
     hidden: bool,
     ignore_case: bool,
     invert_match: bool,
     line_number: bool,
     no_ignore: bool,
+    no_ignore_parent: bool,
     quiet: bool,
+    replace: Option<Vec<u8>>,
     text: bool,
     threads: usize,
     type_defs: Vec<FileTypeDef>,
@@ -194,7 +227,11 @@ impl RawArgs {
         };
         let paths =
             if self.arg_path.is_empty() {
-                vec![Path::new("./").to_path_buf()]
+                if sys::stdin_is_atty() {
+                    vec![Path::new("./").to_path_buf()]
+                } else {
+                    vec![Path::new("-").to_path_buf()]
+                }
             } else {
                 self.arg_path.iter().map(|p| {
                     Path::new(p).to_path_buf()
@@ -232,6 +269,12 @@ impl RawArgs {
             } else {
                 self.flag_threads
             };
+        let color =
+            if self.flag_color == "auto" {
+                sys::stdout_is_atty() || self.flag_pretty
+            } else {
+                self.flag_color == "always"
+            };
         let mut with_filename = self.flag_with_filename;
         if !with_filename {
             with_filename = paths.len() > 1 || paths[0].is_dir();
@@ -240,30 +283,44 @@ impl RawArgs {
         btypes.add_defaults();
         try!(self.add_types(&mut btypes));
         let types = try!(btypes.build());
-        Ok(Args {
+        let mut args = Args {
             pattern: pattern,
             paths: paths,
             after_context: after_context,
             before_context: before_context,
+            color: color,
             context_separator: unescape(&self.flag_context_separator),
             count: self.flag_count,
             eol: eol,
             files: self.flag_files,
             follow: self.flag_follow,
             glob_overrides: glob_overrides,
+            heading: !self.flag_no_heading && self.flag_heading,
             hidden: self.flag_hidden,
             ignore_case: self.flag_ignore_case,
             invert_match: self.flag_invert_match,
-            line_number: self.flag_line_number,
+            line_number: !self.flag_no_line_number && self.flag_line_number,
             no_ignore: self.flag_no_ignore,
+            no_ignore_parent: self.flag_no_ignore_parent,
             quiet: self.flag_quiet,
+            replace: self.flag_replace.clone().map(|s| s.into_bytes()),
             text: self.flag_text,
             threads: threads,
             type_defs: btypes.definitions(),
             type_list: self.flag_type_list,
             types: types,
             with_filename: with_filename,
-        })
+        };
+        // If stdout is a tty, then apply some special default options.
+        if sys::stdout_is_atty() || self.flag_pretty {
+            if !self.flag_no_line_number && !args.count {
+                args.line_number = true;
+            }
+            if !self.flag_no_heading {
+                args.heading = true;
+            }
+        }
+        Ok(args)
     }
 
     fn add_types(&self, types: &mut TypesBuilder) -> Result<()> {
@@ -338,19 +395,26 @@ impl Args {
 
     /// Create a new printer of individual search results that writes to the
     /// writer given.
-    pub fn printer<W: io::Write>(&self, wtr: W) -> Printer<W> {
-        Printer::new(wtr)
+    pub fn printer<W: Send + io::Write>(&self, wtr: W) -> Printer<W> {
+        let mut p = Printer::new(wtr, self.color)
             .context_separator(self.context_separator.clone())
             .eol(self.eol)
+            .heading(self.heading)
             .quiet(self.quiet)
-            .with_filename(self.with_filename)
+            .with_filename(self.with_filename);
+        if let Some(ref rep) = self.replace {
+            p = p.replace(rep.clone());
+        }
+        p
     }
 
     /// Create a new printer of search results for an entire file that writes
     /// to the writer given.
     pub fn out<W: io::Write>(&self, wtr: W) -> Out<W> {
         let mut out = Out::new(wtr);
-        if self.before_context > 0 || self.after_context > 0 {
+        if self.heading && !self.count {
+            out = out.file_separator(b"".to_vec());
+        } else if self.before_context > 0 || self.after_context > 0 {
             out = out.file_separator(self.context_separator.clone());
         }
         out
@@ -364,7 +428,7 @@ impl Args {
     /// Create a new line based searcher whose configuration is taken from the
     /// command line. This searcher supports a dizzying array of features:
     /// inverted matching, line counting, context control and more.
-    pub fn searcher<'a, R: io::Read, W: io::Write>(
+    pub fn searcher<'a, R: io::Read, W: Send + io::Write>(
         &self,
         inp: &'a mut InputBuffer,
         printer: &'a mut Printer<W>,
@@ -399,16 +463,19 @@ impl Args {
     }
 
     /// Create a new recursive directory iterator at the path given.
-    pub fn walker(&self, path: &Path) -> walk::Iter {
+    pub fn walker(&self, path: &Path) -> Result<walk::Iter> {
         let wd = WalkDir::new(path).follow_links(self.follow);
         let mut ig = Ignore::new();
         ig.ignore_hidden(!self.hidden);
         ig.no_ignore(self.no_ignore);
         ig.add_types(self.types.clone());
+        if !self.no_ignore_parent {
+            try!(ig.push_parents(path));
+        }
         if let Some(ref overrides) = self.glob_overrides {
             ig.add_override(overrides.clone());
         }
-        walk::Iter::new(ig, wd)
+        Ok(walk::Iter::new(ig, wd))
     }
 }
 

src/gitignore.rs

@@ -84,6 +84,8 @@ pub struct Gitignore {
     set: glob::Set,
     root: PathBuf,
     patterns: Vec<Pattern>,
+    num_ignores: u64,
+    num_whitelist: u64,
 }
 
 impl Gitignore {
@@ -152,6 +154,16 @@ impl Gitignore {
         }
         Match::None
     }
+
+    /// Returns the total number of ignore patterns.
+    pub fn num_ignores(&self) -> u64 {
+        self.num_ignores
+    }
+
+    /// Returns the total number of whitelisted patterns.
+    pub fn num_whitelist(&self) -> u64 {
+        self.num_whitelist
+    }
 }
 
 /// The result of a glob match.
@@ -238,10 +250,14 @@ impl GitignoreBuilder {
     ///
     /// Once a matcher is built, no new glob patterns can be added to it.
     pub fn build(self) -> Result<Gitignore, Error> {
+        let nignores = self.patterns.iter().filter(|p| !p.whitelist).count();
+        let nwhitelist = self.patterns.iter().filter(|p| p.whitelist).count();
         Ok(Gitignore {
             set: try!(self.builder.build()),
             root: self.root,
             patterns: self.patterns,
+            num_ignores: nignores as u64,
+            num_whitelist: nwhitelist as u64,
         })
     }
 

src/ignore.rs

@@ -15,21 +15,39 @@ of `IgnoreDir`s for use during directory traversal.
 
 use std::error::Error as StdError;
 use std::fmt;
+use std::io;
 use std::path::{Path, PathBuf};
 
-use gitignore::{self, Gitignore, GitignoreBuilder, Match};
+use gitignore::{self, Gitignore, GitignoreBuilder, Match, Pattern};
 use types::Types;
 
+const IGNORE_NAMES: &'static [&'static str] = &[
+    ".gitignore",
+    ".agignore",
+    ".xrepignore",
+];
+
 /// Represents an error that can occur when parsing a gitignore file.
 #[derive(Debug)]
 pub enum Error {
     Gitignore(gitignore::Error),
+    Io {
+        path: PathBuf,
+        err: io::Error,
+    },
+}
+
+impl Error {
+    fn from_io<P: AsRef<Path>>(path: P, err: io::Error) -> Error {
+        Error::Io { path: path.as_ref().to_path_buf(), err: err }
+    }
 }
 
 impl StdError for Error {
     fn description(&self) -> &str {
         match *self {
             Error::Gitignore(ref err) => err.description(),
+            Error::Io { ref err, .. } => err.description(),
         }
     }
 }
@@ -38,6 +56,9 @@ impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             Error::Gitignore(ref err) => err.fmt(f),
+            Error::Io { ref path, ref err } => {
+                write!(f, "{}: {}", path.display(), err)
+            }
         }
     }
 }
@@ -59,9 +80,9 @@ pub struct Ignore {
     stack: Vec<Option<IgnoreDir>>,
     /// A set of override globs that are always checked first. A match (whether
     /// it's whitelist or blacklist) trumps anything in stack.
-    overrides: Option<Gitignore>,
+    overrides: Overrides,
     /// A file type matcher.
-    types: Option<Types>,
+    types: Types,
     ignore_hidden: bool,
     no_ignore: bool,
 }
@@ -71,8 +92,8 @@ impl Ignore {
     pub fn new() -> Ignore {
         Ignore {
             stack: vec![],
-            overrides: None,
-            types: None,
+            overrides: Overrides::new(None),
+            types: Types::empty(),
             ignore_hidden: true,
             no_ignore: false,
         }
@@ -92,17 +113,51 @@ impl Ignore {
 
     /// Add a set of globs that overrides all other match logic.
     pub fn add_override(&mut self, gi: Gitignore) -> &mut Ignore {
-        self.overrides = Some(gi);
+        self.overrides = Overrides::new(Some(gi));
         self
     }
 
     /// Add a file type matcher. The file type matcher has the lowest
     /// precedence.
     pub fn add_types(&mut self, types: Types) -> &mut Ignore {
-        self.types = Some(types);
+        self.types = types;
         self
     }
 
+    /// Push parent directories of `path` on to the stack.
+    pub fn push_parents<P: AsRef<Path>>(
+        &mut self,
+        path: P,
+    ) -> Result<(), Error> {
+        let path = try!(path.as_ref().canonicalize().map_err(|err| {
+            Error::from_io(path.as_ref(), err)
+        }));
+        let mut path = &*path;
+        let mut saw_git = path.join(".git").is_dir();
+        let mut ignore_names = IGNORE_NAMES.to_vec();
+        let mut ignore_dir_results = vec![];
+        while let Some(parent) = path.parent() {
+            if self.no_ignore {
+                ignore_dir_results.push(Ok(None));
+            } else {
+                if saw_git {
+                    ignore_names.retain(|&name| name != ".gitignore");
+                } else {
+                    saw_git = parent.join(".git").is_dir();
+                }
+                let ignore_dir_result =
+                    IgnoreDir::with_ignore_names(parent, ignore_names.iter());
+                ignore_dir_results.push(ignore_dir_result);
+            }
+            path = parent;
+        }
+
+        for ignore_dir_result in ignore_dir_results.into_iter().rev() {
+            try!(self.push_ignore_dir(ignore_dir_result));
+        }
+        Ok(())
+    }
+
     /// Add a directory to the stack.
     ///
     /// Note that even if this returns an error, the directory is added to the
@@ -112,7 +167,17 @@ impl Ignore {
             self.stack.push(None);
             return Ok(());
         }
-        match IgnoreDir::new(path) {
+        self.push_ignore_dir(IgnoreDir::new(path))
+    }
+
+    /// Pushes the result of building a directory matcher on to the stack.
+    ///
+    /// If the result given contains an error, then it is returned.
+    pub fn push_ignore_dir(
+        &mut self,
+        result: Result<Option<IgnoreDir>, Error>,
+    ) -> Result<(), Error> {
+        match result {
             Ok(id) => {
                 self.stack.push(id);
                 Ok(())
@@ -135,11 +200,9 @@ impl Ignore {
     /// Returns true if and only if the given file path should be ignored.
     pub fn ignored<P: AsRef<Path>>(&self, path: P, is_dir: bool) -> bool {
         let path = path.as_ref();
-        if let Some(ref overrides) = self.overrides {
-            let mat = overrides.matched(path, is_dir).invert();
-            if let Some(is_ignored) = self.ignore_match(path, mat) {
-                return is_ignored;
-            }
+        let mat = self.overrides.matched(path, is_dir);
+        if let Some(is_ignored) = self.ignore_match(path, mat) {
+            return is_ignored;
         }
         if self.ignore_hidden && is_hidden(&path) {
             debug!("{} ignored because it is hidden", path.display());
@@ -156,11 +219,9 @@ impl Ignore {
                 break;
             }
         }
-        if let Some(ref types) = self.types {
-            let mat = types.matched(path, is_dir);
-            if let Some(is_ignored) = self.ignore_match(path, mat) {
-                return is_ignored;
-            }
+        let mat = self.types.matched(path, is_dir);
+        if let Some(is_ignored) = self.ignore_match(path, mat) {
+            return is_ignored;
         }
         false
     }
@@ -210,6 +271,23 @@ impl IgnoreDir {
     /// If no ignore glob patterns could be found in the directory then `None`
     /// is returned.
     pub fn new<P: AsRef<Path>>(path: P) -> Result<Option<IgnoreDir>, Error> {
+        IgnoreDir::with_ignore_names(path, IGNORE_NAMES.iter())
+    }
+
+    /// Create a new matcher for the given directory using only the ignore
+    /// patterns found in the file names given.
+    ///
+    /// If no ignore glob patterns could be found in the directory then `None`
+    /// is returned.
+    ///
+    /// Note that the order of the names given is meaningful. Names appearing
+    /// later in the list have precedence over names appearing earlier in the
+    /// list.
+    pub fn with_ignore_names<P: AsRef<Path>, S, I>(
+        path: P,
+        names: I,
+    ) -> Result<Option<IgnoreDir>, Error>
+    where P: AsRef<Path>, S: AsRef<str>, I: Iterator<Item=S> {
         let mut id = IgnoreDir {
             path: path.as_ref().to_path_buf(),
             gi: None,
@@ -217,9 +295,9 @@ impl IgnoreDir {
         let mut ok = false;
         let mut builder = GitignoreBuilder::new(&id.path);
         // The ordering here is important. Later globs have higher precedence.
-        ok = builder.add_path(id.path.join(".gitignore")).is_ok() || ok;
-        ok = builder.add_path(id.path.join(".agignore")).is_ok() || ok;
-        ok = builder.add_path(id.path.join(".xrepignore")).is_ok() || ok;
+        for name in names {
+            ok = builder.add_path(id.path.join(name.as_ref())).is_ok() || ok;
+        }
         if !ok {
             Ok(None)
         } else {
@@ -246,6 +324,56 @@ impl IgnoreDir {
     }
 }
 
+/// Manages a set of overrides provided explicitly by the end user.
+struct Overrides {
+    gi: Option<Gitignore>,
+    unmatched_pat: Pattern,
+}
+
+impl Overrides {
+    /// Creates a new set of overrides from the gitignore matcher provided.
+    /// If no matcher is provided, then the resulting overrides have no effect.
+    fn new(gi: Option<Gitignore>) -> Overrides {
+        Overrides {
+            gi: gi,
+            unmatched_pat: Pattern {
+                from: Path::new("<argv>").to_path_buf(),
+                original: "<none>".to_string(),
+                pat: "<none>".to_string(),
+                whitelist: false,
+                only_dir: false,
+            },
+        }
+    }
+
+    /// Returns a match for the given path against this set of overrides.
+    ///
+    /// If there are no overrides, then this always returns Match::None.
+    ///
+    /// If there is at least one positive override, then this never returns
+    /// Match::None (and interpreting non-matches as ignored) unless is_dir
+    /// is true.
+    pub fn matched<P: AsRef<Path>>(&self, path: P, is_dir: bool) -> Match {
+        // File types don't apply to directories.
+        if is_dir {
+            return Match::None;
+        }
+        let path = path.as_ref();
+        self.gi.as_ref()
+            .map(|gi| {
+                let path = &*path.to_string_lossy();
+                let mat = gi.matched_utf8(path, is_dir).invert();
+                if mat.is_none() && !is_dir {
+                    if gi.num_ignores() > 0 {
+                        return Match::Ignored(&self.unmatched_pat);
+                    }
+                }
+                mat
+            })
+            .unwrap_or(Match::None)
+    }
+}
+
 fn is_hidden<P: AsRef<Path>>(path: P) -> bool {
     if let Some(name) = path.as_ref().file_name() {
         name.to_str().map(|s| s.starts_with(".")).unwrap_or(false)

src/main.rs

@@ -4,9 +4,11 @@ extern crate crossbeam;
 extern crate docopt;
 extern crate env_logger;
 extern crate grep;
-#[cfg(test)]
+#[cfg(windows)]
+extern crate kernel32;
 #[macro_use]
 extern crate lazy_static;
+extern crate libc;
 #[macro_use]
 extern crate log;
 extern crate memchr;
@@ -16,12 +18,15 @@ extern crate parking_lot;
 extern crate regex;
 extern crate regex_syntax as syntax;
 extern crate rustc_serialize;
+extern crate term;
 extern crate thread_local;
 extern crate walkdir;
+#[cfg(windows)]
+extern crate winapi;
 
 use std::error::Error;
 use std::fs::File;
-use std::io::{self, Write};
+use std::io;
 use std::path::Path;
 use std::process;
 use std::result;
@@ -58,6 +63,7 @@ mod ignore;
 mod out;
 mod printer;
 mod search;
+mod sys;
 mod types;
 mod walk;
 
@@ -68,7 +74,7 @@ fn main() {
         Ok(count) if count == 0 => process::exit(1),
         Ok(count) => process::exit(0),
         Err(err) => {
-            let _ = writeln!(&mut io::stderr(), "{}", err);
+            eprintln!("{}", err);
             process::exit(1);
         }
     }
@@ -105,7 +111,7 @@ fn run(args: Args) -> Result<u64> {
         if p == Path::new("-") {
             workq.push(Work::Stdin)
         } else {
-            for ent in args.walker(p) {
+            for ent in try!(args.walker(p)) {
                 workq.push(Work::File(ent));
             }
         }
@@ -121,14 +127,14 @@ fn run(args: Args) -> Result<u64> {
 }
 
 fn run_files(args: Args) -> Result<u64> {
-    let mut printer = Printer::new(io::BufWriter::new(io::stdout()));
+    let mut printer = args.printer(io::BufWriter::new(io::stdout()));
     let mut file_count = 0;
     for p in args.paths() {
         if p == Path::new("-") {
             printer.path(&Path::new("<stdin>"));
             file_count += 1;
         } else {
-            for ent in args.walker(p) {
+            for ent in try!(args.walker(p)) {
                 printer.path(ent.path());
                 file_count += 1;
             }
@@ -138,7 +144,7 @@ fn run_files(args: Args) -> Result<u64> {
 }
 
 fn run_types(args: Args) -> Result<u64> {
-    let mut printer = Printer::new(io::BufWriter::new(io::stdout()));
+    let mut printer = args.printer(io::BufWriter::new(io::stdout()));
     let mut ty_count = 0;
     for def in args.type_defs() {
         printer.type_def(def);
@@ -200,7 +206,7 @@ impl Worker {
         self.match_count
     }
 
-    fn do_work<W: io::Write>(
+    fn do_work<W: Send + io::Write>(
         &mut self,
         printer: &mut Printer<W>,
         work: WorkReady,
@@ -229,7 +235,7 @@ impl Worker {
         }
     }
 
-    fn search<R: io::Read, W: io::Write>(
+    fn search<R: io::Read, W: Send + io::Write>(
         &mut self,
         printer: &mut Printer<W>,
         path: &Path,

src/out.rs

@@ -9,7 +9,7 @@ use std::io::{self, Write};
 pub struct Out<W: io::Write> {
     wtr: io::BufWriter<W>,
     printed: bool,
-    file_separator: Vec<u8>,
+    file_separator: Option<Vec<u8>>,
 }
 
 impl<W: io::Write> Out<W> {
@@ -18,7 +18,7 @@ impl<W: io::Write> Out<W> {
         Out {
             wtr: io::BufWriter::new(wtr),
             printed: false,
-            file_separator: vec![],
+            file_separator: None,
         }
     }
 
@@ -27,16 +27,18 @@ impl<W: io::Write> Out<W> {
     ///
     /// If sep is empty, then no file separator is printed.
     pub fn file_separator(mut self, sep: Vec<u8>) -> Out<W> {
-        self.file_separator = sep;
+        self.file_separator = Some(sep);
         self
     }
 
     /// Write the search results of a single file to the underlying wtr and
     /// flush wtr.
     pub fn write(&mut self, buf: &[u8]) {
-        if self.printed && !self.file_separator.is_empty() {
-            let _ = self.wtr.write_all(&self.file_separator);
-            let _ = self.wtr.write_all(b"\n");
+        if let Some(ref sep) = self.file_separator {
+            if self.printed {
+                let _ = self.wtr.write_all(sep);
+                let _ = self.wtr.write_all(b"\n");
+            }
         }
         let _ = self.wtr.write_all(buf);
         let _ = self.wtr.flush();

src/printer.rs

@@ -1,8 +1,16 @@
-use std::io;
+use std::io::{self, Write};
 use std::path::Path;
+use std::sync::Arc;
+
+use regex::bytes::Regex;
+use term::{self, Terminal};
+use term::color::*;
+use term::terminfo::TermInfo;
 
 use types::FileTypeDef;
 
+use self::Writer::*;
+
 /// Printer encapsulates all output logic for searching.
 ///
 /// Note that we currently ignore all write errors. It's probably worthwhile
@@ -10,7 +18,7 @@ use types::FileTypeDef;
 /// writes to memory, neither of which commonly fail.
 pub struct Printer<W> {
     /// The underlying writer.
-    wtr: W,
+    wtr: Writer<W>,
     /// Whether anything has been printed to wtr yet.
     has_printed: bool,
     /// The string to use to separate non-contiguous runs of context lines.
@@ -19,21 +27,31 @@ pub struct Printer<W> {
     /// printed via the match directly, but occasionally we need to insert them
     /// ourselves (for example, to print a context separator).
     eol: u8,
+    /// Whether to show file name as a heading or not.
+    ///
+    /// N.B. If with_filename is false, then this setting has no effect.
+    heading: bool,
     /// Whether to suppress all output.
     quiet: bool,
+    /// A string to use as a replacement of each match in a matching line.
+    replace: Option<Vec<u8>>,
     /// Whether to prefix each match with the corresponding file name.
     with_filename: bool,
 }
 
-impl<W: io::Write> Printer<W> {
+impl<W: Send + io::Write> Printer<W> {
     /// Create a new printer that writes to wtr.
-    pub fn new(wtr: W) -> Printer<W> {
+    ///
+    /// `color` should be true if the printer should try to use coloring.
+    pub fn new(wtr: W, color: bool) -> Printer<W> {
         Printer {
-            wtr: wtr,
+            wtr: Writer::new(wtr, color),
             has_printed: false,
             context_separator: "--".to_string().into_bytes(),
             eol: b'\n',
+            heading: false,
             quiet: false,
+            replace: None,
             with_filename: false,
         }
     }
@@ -50,12 +68,30 @@ impl<W: io::Write> Printer<W> {
         self
     }
 
+    /// Whether to show file name as a heading or not.
+    ///
+    /// N.B. If with_filename is false, then this setting has no effect.
+    pub fn heading(mut self, yes: bool) -> Printer<W> {
+        self.heading = yes;
+        self
+    }
+
     /// When set, all output is suppressed.
     pub fn quiet(mut self, yes: bool) -> Printer<W> {
         self.quiet = yes;
         self
     }
 
+    /// Replace every match in each matching line with the replacement string
+    /// given.
+    ///
+    /// The replacement string syntax is documented here:
+    /// https://doc.rust-lang.org/regex/regex/bytes/struct.Captures.html#method.expand
+    pub fn replace(mut self, replacement: Vec<u8>) -> Printer<W> {
+        self.replace = Some(replacement);
+        self
+    }
+
     /// When set, each match is prefixed with the file name that it came from.
     pub fn with_filename(mut self, yes: bool) -> Printer<W> {
         self.with_filename = yes;
@@ -70,7 +106,7 @@ impl<W: io::Write> Printer<W> {
     /// Flushes the underlying writer and returns it.
     pub fn into_inner(mut self) -> W {
         let _ = self.wtr.flush();
-        self.wtr
+        self.wtr.into_inner()
     }
 
     /// Prints a type definition.
@@ -120,26 +156,51 @@ impl<W: io::Write> Printer<W> {
 
     pub fn matched<P: AsRef<Path>>(
         &mut self,
+        re: &Regex,
         path: P,
         buf: &[u8],
         start: usize,
         end: usize,
         line_number: Option<u64>,
     ) {
-        if self.with_filename {
+        if self.heading && self.with_filename && !self.has_printed {
+            self.write_heading(path.as_ref());
+        } else if !self.heading && self.with_filename {
             self.write(path.as_ref().to_string_lossy().as_bytes());
             self.write(b":");
         }
         if let Some(line_number) = line_number {
-            self.write(line_number.to_string().as_bytes());
-            self.write(b":");
+            self.line_number(line_number, b':');
+        }
+        if self.replace.is_some() {
+            let line = re.replace_all(
+                &buf[start..end], &**self.replace.as_ref().unwrap());
+            self.write(&line);
+        } else {
+            self.write_match(re, &buf[start..end]);
         }
-        self.write(&buf[start..end]);
         if buf[start..end].last() != Some(&self.eol) {
             self.write_eol();
         }
     }
 
+    pub fn write_match(&mut self, re: &Regex, buf: &[u8]) {
+        if !self.wtr.is_color() {
+            self.write(buf);
+            return;
+        }
+        let mut last_written = 0;
+        for (s, e) in re.find_iter(buf) {
+            self.write(&buf[last_written..s]);
+            let _ = self.wtr.fg(BRIGHT_RED);
+            let _ = self.wtr.attr(term::Attr::Bold);
+            self.write(&buf[s..e]);
+            let _ = self.wtr.reset();
+            last_written = e;
+        }
+        self.write(&buf[last_written..]);
+    }
+
     pub fn context<P: AsRef<Path>>(
         &mut self,
         path: P,
@@ -148,13 +209,18 @@ impl<W: io::Write> Printer<W> {
         end: usize,
         line_number: Option<u64>,
     ) {
-        if self.with_filename {
+        if self.heading && self.with_filename && !self.has_printed {
+            self.write_heading(path.as_ref());
+        } else if !self.heading && self.with_filename {
+            self.write(path.as_ref().to_string_lossy().as_bytes());
+            self.write(b":");
+        }
+        if !self.heading && self.with_filename {
             self.write(path.as_ref().to_string_lossy().as_bytes());
             self.write(b"-");
         }
         if let Some(line_number) = line_number {
-            self.write(line_number.to_string().as_bytes());
-            self.write(b"-");
+            self.line_number(line_number, b'-');
         }
         self.write(&buf[start..end]);
         if buf[start..end].last() != Some(&self.eol) {
@@ -162,6 +228,28 @@ impl<W: io::Write> Printer<W> {
         }
     }
 
+    fn write_heading<P: AsRef<Path>>(&mut self, path: P) {
+        if self.wtr.is_color() {
+            let _ = self.wtr.fg(GREEN);
+        }
+        self.write(path.as_ref().to_string_lossy().as_bytes());
+        self.write_eol();
+        if self.wtr.is_color() {
+            let _ = self.wtr.reset();
+        }
+    }
+
+    fn line_number(&mut self, n: u64, sep: u8) {
+        if self.wtr.is_color() {
+            let _ = self.wtr.fg(YELLOW);
+        }
+        self.write(n.to_string().as_bytes());
+        if self.wtr.is_color() {
+            let _ = self.wtr.reset();
+        }
+        self.write(&[sep]);
+    }
+
     fn write(&mut self, buf: &[u8]) {
         if self.quiet {
             return;
@@ -175,3 +263,154 @@ impl<W: io::Write> Printer<W> {
         self.write(&[eol]);
     }
 }
+
+enum Writer<W> {
+    Colored(term::TerminfoTerminal<W>),
+    NoColor(W),
+}
+
+lazy_static! {
+    static ref TERMINFO: Option<Arc<TermInfo>> = {
+        match term::terminfo::TermInfo::from_env() {
+            Ok(info) => Some(Arc::new(info)),
+            Err(err) => {
+                debug!("error loading terminfo for coloring: {}", err);
+                None
+            }
+        }
+    };
+}
+
+impl<W: Send + io::Write> Writer<W> {
+    fn new(wtr: W, color: bool) -> Writer<W> {
+        // If we want color, build a TerminfoTerminal and see if the current
+        // environment supports coloring. If not, bail with NoColor. To avoid
+        // losing our writer (ownership), do this the long way.
+        if !color || TERMINFO.is_none() {
+            return NoColor(wtr);
+        }
+        // Why doesn't TERMINFO.as_ref().unwrap().clone() work?
+        let info = TERMINFO.clone().unwrap();
+            // names: TERMINFO.as_ref().unwrap().names.clone(),
+            // bools: TERMINFO.as_ref().unwrap().bools.clone(),
+            // numbers: TERMINFO.as_ref().unwrap().numbers.clone(),
+            // strings: TERMINFO.as_ref().unwrap().strings.clone(),
+        // };
+        let tt = term::TerminfoTerminal::new_with_terminfo(wtr, info);
+        if !tt.supports_color() {
+            debug!("environment doesn't support coloring");
+            return NoColor(tt.into_inner());
+        }
+        Colored(tt)
+    }
+
+    fn is_color(&self) -> bool {
+        match *self {
+            Colored(_) => true,
+            NoColor(_) => false,
+        }
+    }
+
+    fn map_result<F>(
+        &mut self,
+        mut f: F,
+    ) -> term::Result<()>
+    where F: FnMut(&mut term::TerminfoTerminal<W>) -> term::Result<()> {
+        match *self {
+            Colored(ref mut w) => f(w),
+            NoColor(_) => Err(term::Error::NotSupported),
+        }
+    }
+
+    fn map_bool<F>(
+        &self,
+        mut f: F,
+    ) -> bool
+    where F: FnMut(&term::TerminfoTerminal<W>) -> bool {
+        match *self {
+            Colored(ref w) => f(w),
+            NoColor(_) => false,
+        }
+    }
+}
+
+impl<W: Send + io::Write> io::Write for Writer<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        match *self {
+            Colored(ref mut w) => w.write(buf),
+            NoColor(ref mut w) => w.write(buf),
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        match *self {
+            Colored(ref mut w) => w.flush(),
+            NoColor(ref mut w) => w.flush(),
+        }
+    }
+}
+
+impl<W: Send + io::Write> term::Terminal for Writer<W> {
+    type Output = W;
+
+    fn fg(&mut self, fg: term::color::Color) -> term::Result<()> {
+        self.map_result(|w| w.fg(fg))
+    }
+
+    fn bg(&mut self, bg: term::color::Color) -> term::Result<()> {
+        self.map_result(|w| w.bg(bg))
+    }
+
+    fn attr(&mut self, attr: term::Attr) -> term::Result<()> {
+        self.map_result(|w| w.attr(attr))
+    }
+
+    fn supports_attr(&self, attr: term::Attr) -> bool {
+        self.map_bool(|w| w.supports_attr(attr))
+    }
+
+    fn reset(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.reset())
+    }
+
+    fn supports_reset(&self) -> bool {
+        self.map_bool(|w| w.supports_reset())
+    }
+
+    fn supports_color(&self) -> bool {
+        self.map_bool(|w| w.supports_color())
+    }
+
+    fn cursor_up(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.cursor_up())
+    }
+
+    fn delete_line(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.delete_line())
+    }
+
+    fn carriage_return(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.carriage_return())
+    }
+
+    fn get_ref(&self) -> &W {
+        match *self {
+            Colored(ref w) => w.get_ref(),
+            NoColor(ref w) => w,
+        }
+    }
+
+    fn get_mut(&mut self) -> &mut W {
+        match *self {
+            Colored(ref mut w) => w.get_mut(),
+            NoColor(ref mut w) => w,
+        }
+    }
+
+    fn into_inner(self) -> W {
+        match self {
+            Colored(w) => w.into_inner(),
+            NoColor(w) => w,
+        }
+    }
+}

src/search.rs

@@ -98,7 +98,7 @@ impl Default for Options {
     }
 }
 
-impl<'a, R: io::Read, W: io::Write> Searcher<'a, R, W> {
+impl<'a, R: io::Read, W: Send + io::Write> Searcher<'a, R, W> {
     /// Create a new searcher.
     ///
     /// `inp` is a reusable input buffer that is used as scratch space by this
@@ -329,7 +329,8 @@ impl<'a, R: io::Read, W: io::Write> Searcher<'a, R, W> {
         self.count_lines(start);
         self.add_line(end);
         self.printer.matched(
-            &self.path, &self.inp.buf, start, end, self.line_count);
+            &self.grep.regex(), &self.path,
+            &self.inp.buf, start, end, self.line_count);
         self.last_printed = end;
         self.after_context_remaining = self.opts.after_context;
     }
@@ -739,7 +740,7 @@ fn main() {
         mut map: F,
     ) -> (u64, String) {
         let mut inp = InputBuffer::with_capacity(1);
-        let mut pp = Printer::new(vec![]).with_filename(true);
+        let mut pp = Printer::new(vec![], false).with_filename(true);
         let grep = GrepBuilder::new(pat).build().unwrap();
         let count = {
             let searcher = Searcher::new(
@@ -755,7 +756,7 @@ fn main() {
         mut map: F,
     ) -> (u64, String) {
         let mut inp = InputBuffer::with_capacity(4096);
-        let mut pp = Printer::new(vec![]).with_filename(true);
+        let mut pp = Printer::new(vec![], false).with_filename(true);
         let grep = GrepBuilder::new(pat).build().unwrap();
         let count = {
             let searcher = Searcher::new(

src/sys.rs

@@ -0,0 +1,139 @@
+/*!
+This io module contains various platform specific functions for detecting
+how xrep is being used. e.g., Is stdin being piped into it? Is stdout being
+redirected to a file? etc... We use this information to tweak various default
+configuration parameters such as colors and match formatting.
+*/
+
+use std::fs::{File, Metadata};
+use std::io;
+
+use libc;
+
+#[cfg(unix)]
+pub fn stdin_is_atty() -> bool {
+    0 < unsafe { libc::isatty(libc::STDIN_FILENO) }
+}
+
+#[cfg(unix)]
+pub fn stdout_is_atty() -> bool {
+    0 < unsafe { libc::isatty(libc::STDOUT_FILENO) }
+}
+
+#[cfg(windows)]
+pub fn stdin_is_atty() -> bool {
+    use kernel32;
+    use winapi;
+
+    unsafe {
+        let fd = winapi::winbase::STD_INPUT_HANDLE;
+        let mut out = 0;
+        kernel32::GetConsoleMode(kernel32::GetStdHandle(fd), &mut out) != 0
+    }
+}
+
+#[cfg(windows)]
+pub fn stdout_is_atty() -> bool {
+    use kernel32;
+    use winapi;
+
+    unsafe {
+        let fd = winapi::winbase::STD_OUTPUT_HANDLE;
+        let mut out = 0;
+        kernel32::GetConsoleMode(handle, &mut out) != 0
+    }
+}
+
+// Probably everything below isn't actually needed. ---AG
+
+#[cfg(unix)]
+pub fn metadata(fd: libc::c_int) -> Result<Metadata, io::Error> {
+    use std::os::unix::io::{FromRawFd, IntoRawFd};
+
+    let f = unsafe { File::from_raw_fd(fd) };
+    let md = f.metadata();
+    // Be careful to transfer ownership back to a simple descriptor. Dropping
+    // the File itself would close the descriptor, which would be quite bad!
+    drop(f.into_raw_fd());
+    md
+}
+
+#[cfg(unix)]
+pub fn stdin_is_file() -> bool {
+    metadata(libc::STDIN_FILENO)
+        .map(|md| md.file_type().is_file())
+        .unwrap_or(false)
+}
+
+#[cfg(unix)]
+pub fn stdout_is_file() -> bool {
+    metadata(libc::STDOUT_FILENO)
+        .map(|md| md.file_type().is_file())
+        .unwrap_or(false)
+}
+
+#[cfg(unix)]
+pub fn stdin_is_char_device() -> bool {
+    use std::os::unix::fs::FileTypeExt;
+
+    metadata(libc::STDIN_FILENO)
+        .map(|md| md.file_type().is_char_device())
+        .unwrap_or(false)
+}
+
+#[cfg(unix)]
+pub fn stdout_is_char_device() -> bool {
+    use std::os::unix::fs::FileTypeExt;
+
+    metadata(libc::STDOUT_FILENO)
+        .map(|md| md.file_type().is_char_device())
+        .unwrap_or(false)
+}
+
+#[cfg(unix)]
+pub fn stdin_is_fifo() -> bool {
+    use std::os::unix::fs::FileTypeExt;
+
+    metadata(libc::STDIN_FILENO)
+        .map(|md| md.file_type().is_fifo())
+        .unwrap_or(false)
+}
+
+#[cfg(unix)]
+pub fn stdout_is_fifo() -> bool {
+    use std::os::unix::fs::FileTypeExt;
+
+    metadata(libc::STDOUT_FILENO)
+        .map(|md| md.file_type().is_fifo())
+        .unwrap_or(false)
+}
+
+#[cfg(windows)]
+pub fn stdin_is_file() -> bool {
+    false
+}
+
+#[cfg(windows)]
+pub fn stdout_is_file() -> bool {
+    false
+}
+
+#[cfg(windows)]
+pub fn stdin_is_char_device() -> bool {
+    false
+}
+
+#[cfg(windows)]
+pub fn stdout_is_char_device() -> bool {
+    false
+}
+
+#[cfg(windows)]
+pub fn stdin_is_fifo() -> bool {
+    false
+}
+
+#[cfg(windows)]
+pub fn stdout_is_fifo() -> bool {
+    false
+}

src/types.rs

@@ -163,6 +163,11 @@ impl Types {
         }
     }
 
+    /// Creates a new file type matcher that never matches.
+    pub fn empty() -> Types {
+        Types::new(None, false)
+    }
+
     /// Returns a match for the given path against this file type matcher.
     ///
     /// The path is considered whitelisted if it matches a selected file type.