Add option to generate a default config file, fixes #870

src/bin/bat/clap_app.rs

@@ -370,6 +370,14 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                 .hidden(true)
                 .help("Show path to the configuration file."),
         )
+        .arg(
+            Arg::with_name("generate-config-file")
+                .long("generate-config-file")
+                .conflicts_with("list-languages")
+                .conflicts_with("list-themes")
+                .hidden(true)
+                .help("Generates a default configuration file."),
+        )
         .arg(
             Arg::with_name("config-dir")
                 .long("config-dir")

src/bin/bat/config.rs

@@ -1,6 +1,7 @@
 use std::env;
 use std::ffi::OsString;
 use std::fs;
+use std::io::{self, Write};
 use std::path::PathBuf;
 
 use shell_words;
@@ -15,6 +16,46 @@ pub fn config_file() -> PathBuf {
         .unwrap_or_else(|| PROJECT_DIRS.config_dir().join("config"))
 }
 
+pub fn generate_config_file() {
+    let config_file = config_file();
+    if config_file.exists() {
+        println!("A config file already exists at: {}", config_file.to_string_lossy());
+
+        print!("Overwrite? (y/n): ");
+        let _ = io::stdout().flush();
+        let mut decision = String::new();
+        io::stdin().read_line(&mut decision).expect("Failed to read input");
+
+        if !decision.trim().eq_ignore_ascii_case("Y") {
+            return;
+        }
+    } else {
+        let config_dir = config_file.parent().unwrap();
+        if !config_dir.exists() {
+            fs::create_dir(config_dir).expect("Unable to create config directory");
+        }
+    }
+
+    let default_config = "# Specify desired theme (e.g. \"TwoDark\")
+#--theme=\"TwoDark\"
+
+# Enable this to use italic text on the terminal (not supported on all terminals):
+#--italic-text=always
+
+# Uncomment the following line to disable automatic paging:
+#--paging=never
+
+# Use C++ syntax for .ino files
+#--map-syntax \"*.ino:C++\"
+
+# Use \".gitignore\"-style highlighting for \".ignore\" files
+#--map-syntax \".ignore:Git Ignore\"
+";
+
+    fs::write(&config_file, default_config).expect("Error writing config file!");
+    println!("Success! Config file written to {}", config_file.to_string_lossy());
+}
+
 pub fn get_args_from_config_file() -> Result<Vec<OsString>, shell_words::ParseError> {
     Ok(fs::read_to_string(config_file())
         .ok()

src/bin/bat/main.rs

@@ -22,7 +22,7 @@ use std::process;
 use ansi_term::Colour::Green;
 use ansi_term::Style;
 
-use crate::{app::App, config::config_file};
+use crate::{app::App, config::{config_file, generate_config_file}};
 use assets::{assets_from_cache_or_binary, cache_dir, clear_assets, config_dir};
 use bat::Controller;
 use directories::PROJECT_DIRS;
@@ -188,6 +188,10 @@ fn run() -> Result<bool> {
             } else if app.matches.is_present("config-file") {
                 println!("{}", config_file().to_string_lossy());
 
+                Ok(true)
+            } else if app.matches.is_present("generate-config-file") {
+                generate_config_file();
+
                 Ok(true)
             } else if app.matches.is_present("config-dir") {
                 writeln!(io::stdout(), "{}", config_dir())?;