feat: add Backend.AI branding to help output and simplify no-arg usage

Author: inureyes

src/cli.rs

@@ -19,10 +19,10 @@ use std::path::PathBuf;
 #[command(
     name = "bssh",
     version,
-    before_help = "",
+    before_help = "\n\nBackend.AI SSH - Parallel command execution across cluster nodes",
     about = "Backend.AI SSH - SSH-compatible parallel command execution tool",
-    long_about = "bssh is a high-performance SSH client with parallel execution capabilities.\nIt can be used as a drop-in replacement for SSH (single host) or as a powerful cluster management tool (multiple hosts).\n\nSSH Compatibility Mode:\n  bssh user@host                    # Interactive shell\n  bssh user@host command            # Execute command\n  bssh -p 2222 user@host            # Custom port\n  bssh -i key.pem user@host         # Custom key\n\nMulti-Server Mode:\n  bssh -C production \"uptime\"       # Execute on cluster\n  bssh -H \"host1,host2\" \"df -h\"     # Execute on hosts\n\nThe tool provides secure file transfer using SFTP and supports SSH keys, SSH agent, and password authentication.\nIt automatically detects Backend.AI multi-node session environments.",
-    after_help = "EXAMPLES:\n  SSH Mode:\n    bssh user@host                         # Interactive shell\n    bssh admin@server.com \"uptime\"         # Execute command\n    bssh -p 2222 -i ~/.ssh/key user@host   # Custom port and key\n\n  Multi-Server Mode:\n    bssh -C production \"systemctl status\"  # Use cluster config\n    bssh -H \"web1,web2,web3\" \"df -h\"      # Direct hosts\n\n  File Operations:\n    bssh -C staging upload file.txt /tmp/  # Upload to cluster\n    bssh -H host1,host2 download /etc/hosts ./backups/\n\n  Other Commands:\n    bssh list                              # List configured clusters\n    bssh -C production ping                # Test connectivity\n\nFor more information: https://github.com/lablup/bssh"
+    long_about = "bssh is a high-performance SSH client with parallel execution capabilities.\nIt can be used as a drop-in replacement for SSH (single host) or as a powerful cluster management tool (multiple hosts).\n\nThe tool provides secure file transfer using SFTP and supports SSH keys, SSH agent, and password authentication.\nIt automatically detects Backend.AI multi-node session environments.",
+    after_help = "EXAMPLES:\n  SSH Mode:\n    bssh user@host                         # Interactive shell\n    bssh admin@server.com \"uptime\"         # Execute command\n    bssh -p 2222 -i ~/.ssh/key user@host   # Custom port and key\n\n  Multi-Server Mode:\n    bssh -C production \"systemctl status\"  # Use cluster config\n    bssh -H \"web1,web2,web3\" \"df -h\"      # Direct hosts\n\n  File Operations:\n    bssh -C staging upload file.txt /tmp/  # Upload to cluster\n    bssh -H host1,host2 download /etc/hosts ./backups/\n\n  Other Commands:\n    bssh list                              # List configured clusters\n    bssh -C production ping                # Test connectivity\n\nDeveloped and maintained as part of the Backend.AI project.\nFor more information: https://github.com/lablup/bssh"
 )]
 pub struct Cli {
     /// SSH destination in format: [user@]hostname[:port] or ssh://[user@]hostname[:port]

src/main.rs

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 use anyhow::Result;
-use clap::{CommandFactory, Parser};
+use clap::Parser;
 use std::path::{Path, PathBuf};
 use std::time::Duration;
 
@@ -34,11 +34,17 @@ use bssh::{
     utils::init_logging,
 };
 
-/// Show help message and exit
-fn show_help() {
-    let mut cmd = Cli::command();
-    let _ = cmd.print_help();
-    eprintln!(); // Add a newline after help
+/// Show concise usage message (like SSH)
+fn show_usage() {
+    println!("usage: bssh [-46AqtTvx] [-C cluster] [-F configfile] [-H hosts]");
+    println!("           [-i identity_file] [-J destination] [-l login_name]");
+    println!("           [-o option] [-p port] [--config config] [--parallel N]");
+    println!("           [--output-dir dir] [--timeout seconds] [--use-agent]");
+    println!("           destination [command [argument ...]]");
+    println!("       bssh [-Q query_option]");
+    println!("       bssh [exec|list|ping|upload|download|interactive] ...");
+    println!();
+    println!("For more information, try 'bssh --help'");
 }
 
 /// Format a Duration into a human-readable string
@@ -72,8 +78,8 @@ async fn main() -> Result<()> {
     // Check if no arguments were provided
     let args: Vec<String> = std::env::args().collect();
     if args.len() == 1 {
-        // Show help when no arguments provided
-        show_help();
+        // Show concise usage when no arguments provided (like SSH)
+        show_usage();
         std::process::exit(0);
     }