Add exemplary hexyl plugin

* Make the default macOS theme depend on Dark Mode

We frequently get complaints from macOS users that bat does not work on
their default macOS terminal background, which is white.

Pay the price of slightly increased startup time to get a better default
on macOS. To avoid the slightly increased startup time, simply specify a
theme explicitly via `--theme`, `BAT_THEME`, or `~/.config/bat`.

Note that if there is an error when we check if Dark Mode is enabled, we
behave the same as on Windows and Linux; assume that the terminal
background is dark. This harmonizes behavior across platforms, and makes
bat behave the same as before, when Dark Mode was always assumed to be
enabled.

* src/assets.rs: Fix typo

* Update CHANGELOG.md

.github/ISSUE_TEMPLATE/question.md

@@ -7,3 +7,5 @@ assignees: ''
 
 ---
 
+<!-- Using a normal ticket is still fine, but feel free to ask your
+questions about bat on https://github.com/sharkdp/bat/discussions instead. -->

.github/workflows/CICD.yml

@@ -154,7 +154,7 @@ jobs:
           - { target: x86_64-apple-darwin         , os: macos-10.15                   }
           - { target: x86_64-pc-windows-gnu       , os: windows-2019                  }
           - { target: x86_64-pc-windows-msvc      , os: windows-2019                  }
-          - { target: x86_64-unknown-linux-gnu    , os: ubuntu-20.04                  }
+          - { target: x86_64-unknown-linux-gnu    , os: ubuntu-20.04, use-cross: true }
           - { target: x86_64-unknown-linux-musl   , os: ubuntu-20.04, use-cross: true }
     steps:
     - name: Checkout source code

CHANGELOG.md

@@ -1,3 +1,22 @@
+# unreleased
+
+## Features
+
+- Make the default macOS theme depend on Dark Mode. See #2197, #1746 (@Enselic)
+
+## Bugfixes
+
+## Other
+
+- Relaxed glibc requirements on amd64, see #2106 and #2194 (@sharkdp)
+
+## Syntaxes
+
+## Themes
+
+## `bat` as a library
+
+
 # v0.21.0
 
 ## Features
@@ -30,8 +49,6 @@
 - Slightly adjust Zig syntax. See #2136 (@Enselic)
 - Associate `.inf` files with the `INI` syntax. See #2190 (@Enselic)
 
-## Themes
-
 ## `bat` as a library
 
 - Allow configuration of `show_nonprintable` with `PrettyPrinter`, see #2142

Cargo.lock

@@ -98,6 +98,7 @@ dependencies = [
  "path_abs",
  "predicates",
  "regex",
+ "rlua",
  "semver",
  "serde",
  "serde_yaml",
@@ -916,6 +917,30 @@ dependencies = [
  "bytemuck",
 ]
 
+[[package]]
+name = "rlua"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "627ae78424400009e889c43b0c188d0b7af3fe7301b68c03d9cfacb29115408a"
+dependencies = [
+ "bitflags",
+ "bstr",
+ "libc",
+ "num-traits",
+ "rlua-lua54-sys",
+]
+
+[[package]]
+name = "rlua-lua54-sys"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4e1fdfc6a5f7acfa1b1fe26c5076b54f5ebd6818b5982460c39844c8b859370"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.6"

Cargo.toml

@@ -30,6 +30,7 @@ minimal-application = [
     "paging",
     "regex-onig",
     "wild",
+    "rlua"
 ]
 git = ["git2"] # Support indicating git modifications
 paging = ["shell-words", "grep-cli"] # Support applying a pager on the output
@@ -65,6 +66,7 @@ grep-cli = { version = "0.1.6", optional = true }
 regex = { version = "1.5.5", optional = true }
 walkdir = { version = "2.0", optional = true }
 bytesize = { version = "1.1.0" }
+rlua = { version = "0.19", optional = true }
 
 [dependencies.git2]
 version = "0.14"

plugins/curl.lua

@@ -0,0 +1,21 @@
+function tempdir()
+    local stream = assert(io.popen('mktemp --directory'))
+    local output = stream:read('*all')
+    stream:close()
+    return string.gsub(output, "\n", "")
+end
+
+function preprocess(path_or_url)
+    filename_from_url = string.match(path_or_url, '^https?://.*/(.*)$')
+    if filename_from_url then
+        local temp_directory = tempdir()
+        local new_path = temp_directory .. "/" .. filename_from_url
+
+        -- TODO: how to prevent shell injection bugs?
+        os.execute("curl --silent '" .. path_or_url .. "' --output '" .. new_path .. "'")
+
+        return new_path
+    else
+        return path_or_url
+    end
+end

plugins/directories.lua

@@ -0,0 +1,17 @@
+-- https://stackoverflow.com/a/3254007/704831
+function is_dir(path)
+    local f = io.open(path, "r")
+    local ok, err, code = f:read(1)
+    f:close()
+    return code == 21
+end
+
+function preprocess(path)
+    if is_dir(path) then
+        tmpfile = os.tmpname()
+        os.execute("ls -alh --color=always '" .. path .. "' > '" .. tmpfile .. "'")
+        return tmpfile
+    else
+        return path
+    end
+end

plugins/hexyl.lua

@@ -0,0 +1,21 @@
+-- Note: this plugin depends on the existence of 'inspect' [1] and 'hexyl' [2]
+--
+-- [1] https://github.com/sharkdp/content_inspector
+-- [2] https://github.com/sharkdp/hexyl
+
+function is_binary(path)
+    local stream = assert(io.popen("inspect '" .. path .. "'"))
+    local output = stream:read('*all')
+    stream:close()
+    return string.find(output, ": binary\n")
+end
+
+function preprocess(path)
+    if is_binary(path) then
+        tmpfile = os.tmpname()
+        os.execute("hexyl --length 1024 --no-position --border=none --no-squeezing '" .. path .. "' > '" .. tmpfile .. "'")
+        return tmpfile
+    else
+        return path
+    end
+end

plugins/uncompress.lua

@@ -0,0 +1,21 @@
+function tempdir()
+    local stream = assert(io.popen('mktemp --directory'))
+    local output = stream:read('*all')
+    stream:close()
+    return string.gsub(output, "\n", "")
+end
+
+function preprocess(path)
+    prefix = string.match(path, '^(.*)%.gz$')
+    if prefix then
+        local temp_directory = tempdir()
+        local new_path = temp_directory .. "/" .. prefix
+
+        -- TODO: how to prevent shell injection bugs?
+        os.execute("gunzip < '" .. path .. "' > '" .. new_path .. "'")
+
+        return new_path
+    else
+        return path
+    end
+end

src/assets.rs

@@ -69,10 +69,57 @@ impl HighlightingAssets {
         }
     }
 
+    /// The default theme.
+    ///
+    /// ### Windows and Linux
+    ///
+    /// Windows and most Linux distributions has a dark terminal theme by
+    /// default. On these platforms, this function always returns a theme that
+    /// looks good on a dark background.
+    ///
+    /// ### macOS
+    ///
+    /// On macOS the default terminal background is light, but it is common that
+    /// Dark Mode is active, which makes the terminal background dark. On this
+    /// platform, the default theme depends on
+    /// ```bash
+    /// defaults read -globalDomain AppleInterfaceStyle
+    /// ````
+    /// To avoid the overhead of the check on macOS, simply specify a theme
+    /// explicitly via `--theme`, `BAT_THEME`, or `~/.config/bat`.
+    ///
+    /// See <https://github.com/sharkdp/bat/issues/1746> and
+    /// <https://github.com/sharkdp/bat/issues/1928> for more context.
     pub fn default_theme() -> &'static str {
+        #[cfg(not(target_os = "macos"))]
+        {
+            Self::default_dark_theme()
+        }
+        #[cfg(target_os = "macos")]
+        {
+            if macos_dark_mode_active() {
+                Self::default_dark_theme()
+            } else {
+                Self::default_light_theme()
+            }
+        }
+    }
+
+    /**
+     * The default theme that looks good on a dark background.
+     */
+    fn default_dark_theme() -> &'static str {
         "Monokai Extended"
     }
 
+    /**
+     * The default theme that looks good on a light background.
+     */
+    #[cfg(target_os = "macos")]
+    fn default_light_theme() -> &'static str {
+        "Monokai Extended Light"
+    }
+
     pub fn from_cache(cache_path: &Path) -> Result<Self> {
         Ok(HighlightingAssets::new(
             SerializedSyntaxSet::FromFile(cache_path.join("syntaxes.bin")),
@@ -352,6 +399,16 @@ fn asset_from_cache<T: serde::de::DeserializeOwned>(
         .map_err(|_| format!("Could not parse cached {}", description).into())
 }
 
+#[cfg(target_os = "macos")]
+fn macos_dark_mode_active() -> bool {
+    let mut defaults_cmd = std::process::Command::new("defaults");
+    defaults_cmd.args(&["read", "-globalDomain", "AppleInterfaceStyle"]);
+    match defaults_cmd.output() {
+        Ok(output) => output.stdout == b"Dark\n",
+        Err(_) => true,
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/bin/bat/app.rs

@@ -241,6 +241,11 @@ impl App {
                 .map(HighlightedLineRanges)
                 .unwrap_or_default(),
             use_custom_assets: !self.matches.is_present("no-custom-assets"),
+            plugins: self
+                .matches
+                .values_of_os("load-plugin")
+                .unwrap_or_default()
+                .collect(),
         })
     }
 

src/bin/bat/clap_app.rs

@@ -474,6 +474,16 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                 .help("Display all supported languages.")
                 .long_help("Display a list of supported languages for syntax highlighting."),
         )
+        .arg(
+            Arg::with_name("load-plugin")
+            .long("load-plugin")
+            .multiple(true)
+            .takes_value(true)
+            .number_of_values(1)
+            .value_name("name")
+            .help("Load plugin with specified name.")
+            .hidden_short_help(true)
+        )
         .arg(
             Arg::with_name("unbuffered")
                 .short("u")

src/bin/bat/main.rs

@@ -8,6 +8,7 @@ mod directories;
 mod input;
 
 use std::collections::{HashMap, HashSet};
+use std::ffi::OsStr;
 use std::io;
 use std::io::{BufReader, Write};
 use std::path::Path;
@@ -218,7 +219,66 @@ pub fn list_themes(cfg: &Config) -> Result<()> {
     Ok(())
 }
 
-fn run_controller(inputs: Vec<Input>, config: &Config) -> Result<bool> {
+fn load_and_run_preprocess_plugins(plugins: &[&OsStr], inputs: &mut Vec<Input>) -> Result<()> {
+    use bat::input::InputKind;
+    use rlua::{Function, Lua, Result as LuaResult};
+    use std::fs;
+    use std::path::PathBuf;
+
+    if plugins.is_empty() {
+        // Do not create Lua context if there are no plugins
+        return Ok(());
+    }
+
+    let lua = Lua::new();
+
+    for plugin_name in plugins {
+        // TODO: properly load plugins from a central directory + user directories
+        // TODO: how to handle plugin priority?
+        let mut plugin_path = PathBuf::from("plugins");
+        plugin_path.push(plugin_name);
+
+        let plugin_source_code = fs::read_to_string(&plugin_path).map_err(|e| {
+            format!(
+                "Could not load bat plugin '{}': {}",
+                plugin_path.to_string_lossy(),
+                e
+            )
+        })?;
+
+        lua.context::<_, LuaResult<()>>(|lua_ctx| {
+            let globals = lua_ctx.globals();
+
+            lua_ctx.load(&plugin_source_code).exec()?;
+
+            // Plugins are expected to have a 'preprocess' function
+            let preprocess: Function = globals.get("preprocess")?;
+
+            for input in inputs.iter_mut() {
+                if let InputKind::OrdinaryFile(ref mut path) = &mut input.kind {
+                    let path_str: String = path.to_string_lossy().into();
+                    let new_path = preprocess.call::<_, String>(path_str)?;
+
+                    *path = PathBuf::from(new_path);
+
+                    // TODO: the following line overwrites actual user provided names. However,
+                    // this is necessary to get proper syntax highlighting for the path that
+                    // is being provided by the plugin.
+                    input.metadata.user_provided_name = Some(path.clone());
+                }
+            }
+
+            Ok(())
+        })
+        .map_err(|e| format!("Error while executing Lua code: {}", e))?;
+    }
+
+    Ok(())
+}
+
+fn run_controller(mut inputs: Vec<Input>, config: &Config) -> Result<bool> {
+    load_and_run_preprocess_plugins(&config.plugins, &mut inputs)?;
+
     let assets = assets_from_cache_or_binary(config.use_custom_assets)?;
     let controller = Controller::new(config, &assets);
     controller.run(inputs)

src/config.rs

@@ -5,6 +5,8 @@ use crate::style::StyleComponents;
 use crate::syntax_mapping::SyntaxMapping;
 use crate::wrapping::WrappingMode;
 
+use std::ffi::OsStr;
+
 #[derive(Debug, Clone)]
 pub enum VisibleLines {
     /// Show all lines which are included in the line ranges
@@ -86,6 +88,9 @@ pub struct Config<'a> {
     /// Whether or not to allow custom assets. If this is false or if custom assets (a.k.a.
     /// cached assets) are not available, assets from the binary will be used instead.
     pub use_custom_assets: bool,
+
+    /// List of bat plugins to be loaded
+    pub plugins: Vec<&'a OsStr>,
 }
 
 #[cfg(all(feature = "minimal-application", feature = "paging"))]

src/input.rs

@@ -69,7 +69,8 @@ impl InputDescription {
     }
 }
 
-pub(crate) enum InputKind<'a> {
+pub enum InputKind<'a> {
+    // TODO
     OrdinaryFile(PathBuf),
     StdIn,
     CustomReader(Box<dyn Read + 'a>),
@@ -86,14 +87,15 @@ impl<'a> InputKind<'a> {
 }
 
 #[derive(Clone, Default)]
-pub(crate) struct InputMetadata {
-    pub(crate) user_provided_name: Option<PathBuf>,
+pub struct InputMetadata {
+    // TODO
+    pub user_provided_name: Option<PathBuf>,
     pub(crate) size: Option<u64>,
 }
 
 pub struct Input<'a> {
-    pub(crate) kind: InputKind<'a>,
-    pub(crate) metadata: InputMetadata,
+    pub kind: InputKind<'a>,     // TODO
+    pub metadata: InputMetadata, // TODO
     pub(crate) description: InputDescription,
 }
 

tests/integration_tests.rs

@@ -1427,6 +1427,8 @@ fn ansi_passthrough_emit() {
 fn ignored_suffix_arg() {
     bat()
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("test.json~")
         .assert()
@@ -1436,6 +1438,8 @@ fn ignored_suffix_arg() {
 
     bat()
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("--ignored-suffix=.suffix")
         .arg("test.json.suffix")
@@ -1446,6 +1450,8 @@ fn ignored_suffix_arg() {
 
     bat()
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("test.json.suffix")
         .assert()
@@ -1463,6 +1469,8 @@ fn highlighting_is_skipped_on_long_lines() {
 
     bat()
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("longline.json")
         .assert()
@@ -1482,6 +1490,8 @@ fn all_global_git_config_locations_syntax_mapping_work() {
     bat()
         .env("XDG_CONFIG_HOME", fake_home.join(".config").as_os_str())
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("git/.config/git/config")
         .assert()
@@ -1492,6 +1502,8 @@ fn all_global_git_config_locations_syntax_mapping_work() {
     bat()
         .env("HOME", fake_home.as_os_str())
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("git/.config/git/config")
         .assert()
@@ -1502,6 +1514,8 @@ fn all_global_git_config_locations_syntax_mapping_work() {
     bat()
         .env("HOME", fake_home.as_os_str())
         .arg("-f")
+        .arg("--theme")
+        .arg("Monokai Extended")
         .arg("-p")
         .arg("git/.gitconfig")
         .assert()