Get current juliaup channel with juliaup self channel

src/cli.rs

@@ -103,11 +103,10 @@ pub enum SelfSubCmd {
  /// Update the Julia versions database and juliaup itself
  Update {},
  #[cfg(feature = "selfupdate")]
- #[command(arg_required_else_help = true)]
- /// Configure the channel to use for juliaup updates.
+ /// Configure the channel to use for juliaup updates. Leave CHANNEL blank to see current channel.
  Channel {
  #[arg(value_enum)]
- channel: JuliaupChannel,
+ channel: Option<JuliaupChannel>,
  },
  #[cfg(feature = "selfupdate")]
  /// Uninstall this version of juliaup from the system

src/command_selfchannel.rs

@@ -3,7 +3,7 @@ use anyhow::Result;
 
 #[cfg(feature = "selfupdate")]
 pub fn run_command_selfchannel(
- channel: crate::cli::JuliaupChannel,
+ channel: Option<crate::cli::JuliaupChannel>,
  paths: &crate::global_paths::GlobalPaths,
 ) -> Result<()> {
  use crate::config_file::{load_mut_config_db, save_config_db};
@@ -12,10 +12,19 @@ pub fn run_command_selfchannel(
  let mut config_file = load_mut_config_db(paths)
  .with_context(|| "`self update` command failed to load configuration data.")?;
 
- config_file.self_data.juliaup_channel = Some(channel.to_lowercase().to_string());
-
- save_config_db(&mut config_file)
- .with_context(|| "`selfchannel` command failed to save configuration db.")?;
+ match channel {
+ Some(chan) => {
+ config_file.self_data.juliaup_channel = Some(chan.to_lowercase().to_string());
+ save_config_db(&mut config_file)?;
+ }
+ None => {
+ let channel_name = config_file
+ .self_data
+ .juliaup_channel
+ .expect("juliaup_channel should not be empty.");
+ println!("Your juliaup is currently on channel `{}`. Run `juliaup self channel -h` for help on how to set the juliaup channel.", channel_name);
+ }
+ }
 
  Ok(())
 }