feat(client): add --port option to specify server port

Allow users to override the default TFTP port (69) when connecting
to servers running on non-standard ports. The port can be specified
via -p or --port flag.

Examples:
  tftp -p 6969 get 192.168.1.1 config.txt
  tftp --port 1069 put myserver firmware.bin

If a port is embedded in the host (host:port format), the --port
option takes precedence.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

crates/pfs-tftp/src/bin/tftp.rs

@@ -12,6 +12,7 @@
 //!   put <HOST> <LOCAL_FILE> [REMOTE_FILE]    Upload a file
 //!
 //! Options:
+//!   -p, --port <PORT>    Server port (default: 69)
 //!   -m, --mode <MODE>    Transfer mode: octet (default) or netascii
 //!   -v, --verbose        Enable verbose output
 //!   -h, --help           Print help
@@ -23,8 +24,8 @@
 //! # Download a file
 //! tftp get 192.168.1.1 config.txt
 //!
-//! # Download to a specific local file
+//! # Download from a custom port
-//! tftp get 192.168.1.1 config.txt local_config.txt
+//! tftp -p 6969 get 192.168.1.1 config.txt
 //!
 //! # Upload a file
 //! tftp put 192.168.1.1 firmware.bin
@@ -48,14 +49,15 @@ fn print_usage(program: &str) {
     eprintln!("  put <HOST> <LOCAL_FILE> [REMOTE_FILE]    Upload a file");
     eprintln!();
     eprintln!("Options:");
+    eprintln!("  -p, --port <PORT>    Server port (default: 69)");
     eprintln!("  -m, --mode <MODE>    Transfer mode: octet (default) or netascii");
     eprintln!("  -v, --verbose        Enable verbose output");
     eprintln!("  -h, --help           Print help");
     eprintln!();
     eprintln!("Examples:");
     eprintln!("  {program} get 192.168.1.1 config.txt");
-    eprintln!("  {program} put 192.168.1.1 firmware.bin");
+    eprintln!("  {program} -p 6969 get 192.168.1.1 config.txt");
-    eprintln!("  {program} -m netascii get 192.168.1.1:69 readme.txt local.txt");
+    eprintln!("  {program} -m netascii put 192.168.1.1 readme.txt");
 }
 
 /// Command to execute.
@@ -75,6 +77,7 @@ enum Command {
 /// Parsed command-line arguments.
 struct Args {
     command: Command,
+    port: Option<u16>,
     mode: Mode,
     verbose: bool,
 }
@@ -84,6 +87,7 @@ fn parse_args() -> Result<Args, String> {
     let args: Vec<String> = env::args().collect();
     let program = &args[0];
 
+    let mut port: Option<u16> = None;
     let mut mode = Mode::Octet;
     let mut verbose = false;
 
@@ -96,6 +100,17 @@ fn parse_args() -> Result<Args, String> {
                 print_usage(program);
                 std::process::exit(0);
             }
+            "-p" | "--port" => {
+                i += 1;
+                if i >= args.len() {
+                    return Err("--port requires an argument".to_string());
+                }
+                port = Some(
+                    args[i]
+                        .parse()
+                        .map_err(|_| format!("invalid port: {}", args[i]))?,
+                );
+            }
             "-m" | "--mode" => {
                 i += 1;
                 if i >= args.len() {
@@ -172,14 +187,23 @@ fn parse_args() -> Result<Args, String> {
 
     Ok(Args {
         command,
+        port,
         mode,
         verbose,
     })
 }
 
-/// Format host for connection (add default port if needed).
+/// Format host for connection.
-fn format_host(host: &str) -> String {
+///
-    if host.contains(':') {
+/// If a port override is provided, it is used. Otherwise, if the host already
+/// contains a port (has ':'), it is used as-is. Otherwise, the default TFTP
+/// port 69 is appended.
+fn format_host(host: &str, port_override: Option<u16>) -> String {
+    if let Some(port) = port_override {
+        // Strip any existing port from host and use override
+        let host_part = host.split(':').next().unwrap_or(host);
+        format!("{host_part}:{port}")
+    } else if host.contains(':') {
         host.to_string()
     } else {
         format!("{host}:69")
@@ -203,7 +227,7 @@ fn main() -> ExitCode {
             remote_file,
             local_file,
         } => {
-            let addr = format_host(&host);
+            let addr = format_host(&host, args.port);
 
             if args.verbose {
                 eprintln!("Getting '{remote_file}' from {addr} -> '{local_file}'");
@@ -255,7 +279,7 @@ fn main() -> ExitCode {
             local_file,
             remote_file,
         } => {
-            let addr = format_host(&host);
+            let addr = format_host(&host, args.port);
 
             if args.verbose {
                 eprintln!("Putting '{local_file}' -> {addr} as '{remote_file}'");