add optional config path arg

README.md

@@ -32,8 +32,9 @@ A desktop notification server, like [Dunst](https://dunst-project.org/)
 
 ### Configuration
 
-The binary looks for the config file `bato.toml` located in
-`$XDG_CONFIG_HOME/bato/` (default to `$HOME/.config/bato/`).\
+By default, bato looks for the config file `~/.config/bato/bato.toml`
+( $XDG_CONFIG_HOME/bato/bato.toml ).\
+To use a custom file, run with the `--config` flag.\
 If the config file is not found, bato prints an error and exits.
 
 All config options are detailed [here](https://github.com/doums/bato/blob/master/bato.toml).

src/cli.rs

@@ -2,6 +2,8 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+use std::path::PathBuf;
+
 use clap::{Parser, ValueEnum};
 use serde::Deserialize;
 
@@ -36,4 +38,8 @@ pub struct Cli {
     /// Set the log level
     #[arg(short = 'L', long)]
     pub log_level: Option<LogLevel>,
+
+    /// Use a custom config file
+    #[arg(short = 'c', long, value_name = "FILE")]
+    pub config: Option<PathBuf>,
 }

src/config.rs

@@ -61,15 +61,17 @@ pub struct Config {
 
 impl Config {
     #[instrument]
-    pub fn new() -> anyhow::Result<Self> {
-        let home = env::var("HOME")?;
-        let mut config_dir = env::var(XDG_CONFIG_HOME)
-            .map(PathBuf::from)
-            .unwrap_or_else(|_| Path::new(&home).join(".config"));
-        config_dir.push(APP_DIR);
-        util::check_dir_or_create(&config_dir)?;
+    pub fn new(config_path: Option<PathBuf>) -> anyhow::Result<Self> {
+        let config_file = config_path.unwrap_or({
+            let home = env::var("HOME")?;
+            let mut config_dir = env::var(XDG_CONFIG_HOME)
+                .map(PathBuf::from)
+                .unwrap_or_else(|_| Path::new(&home).join(".config"));
+            config_dir.push(APP_DIR);
+            util::check_dir_or_create(&config_dir)?;
 
-        let config_file = config_dir.join(CONFIG_FILE);
+            config_dir.join(CONFIG_FILE)
+        });
         info!("config file: {:?}", config_file);
         let content = fs::read_to_string(&config_file).map_err(|e| {
             let error = format!(

src/main.rs

@@ -18,7 +18,7 @@ fn main() -> Result<()> {
 
     signal::catch_signals()?;
 
-    let config = Config::new()?;
+    let config = Config::new(cli.config)?;
     trace!("{:#?}", config);
     debug!("tick rate {}s", config.tick_rate);
     let tick = Duration::from_secs(config.tick_rate as u64);