Add option to append to local ignore file

src/app.rs

@@ -65,7 +65,10 @@ pub enum Command {
     /// Add a line to the gitignore
     Add {
         /// The glob string that should be added
-        glob: String,
+        glob:  String,
+        /// Add the entry to the repo local ignore file
+        #[structopt(short)]
+        local: bool,
     },
     /// Download a gitignore for a language
     Get {
@@ -87,7 +90,7 @@ pub enum Command {
 }
 
 /// Runs the command `add`
-fn run_add(glob: &str) -> Result<()> {
+fn run_add(glob: &str, local: bool) -> Result<()> {
     trace!("running command `add` with glob '{}'", &glob);
     let root = match git_dir()? {
         Some(r) => r,
@@ -96,7 +99,11 @@ fn run_add(glob: &str) -> Result<()> {
     info!("Working with git root in {:?}", root);
 
     let mut file_path = PathBuf::from(&root);
-    file_path.push(".gitignore");
+    if local {
+        file_path.push(".git/info/exclude")
+    } else {
+        file_path.push(".gitignore");
+    }
     let gitig = Gitignore::from_path(&file_path);
     gitig.add_line(glob)?;
     debug!("Added '{}' to {}", glob, gitig);
@@ -158,7 +165,7 @@ fn run_dump_completion(shell: Option<structopt::clap::Shell>) -> Result<()> {
 /// The actual `main()`
 pub fn main(opts: CliOpts) -> Result<()> {
     match opts.cmd {
-        Command::Add { glob } => run_add(&glob)?,
+        Command::Add { glob, local } => run_add(&glob, local)?,
         Command::Get { lang, append } => run_get(&lang, append)?,
         Command::ListTemplates => run_list_templates()?,
         Command::DumpCompletions { shell } => run_dump_completion(shell)?,