feat: add --list-formats command, support auto-generated man pages

Cargo.toml

@@ -24,15 +24,26 @@ extended-description = "A program attempting to be a universal file converter"
 depends = "ffmpeg, $auto"
 section = "utility"
 priority = "optional"
+assets = [
+    ["target/release/convertis", "usr/bin/", "755"],
+    ["README.md", "usr/share/doc/convertis/README", "644"],
+    ["target/man/convertis.1", "usr/share/man/man1/convertis.1", "644"]
+]
 
 [package.metadata.generate-rpm]
 assets = [
-    { source = "target/release/convertis", dest = "/usr/bin/convertis", mode = "755" }
+    { source = "target/release/convertis", dest = "/usr/bin/convertis", mode = "755" },
+    { source = "target/man/convertis.1", dest = "/usr/share/man/man1/convertis.1", mode = "644" }
 ]
 
 [package.metadata.generate-rpm.requires]
 ffmpeg = "*"
 
+[build-dependencies]
+clap = { version = "4.6.1", features = ["derive"] }
+clap_mangen = "0.2"
+tracing = "0.1.44"
+
 [dependencies]
 clap = { version = "4.6.1", features = ["derive"] }
 image = "0.25.10"

build.rs

@@ -16,6 +16,10 @@ use std::env;
 use std::fs;
 use std::path::Path;
 use std::process::Command;
+use clap::CommandFactory;
+
+#[path = "src/args.rs"]
+mod args;
 
 fn run_command(cmd: &str, args: &[&str]) -> Option<String> {
     let output = Command::new(cmd).args(args).output().ok()?;
@@ -104,4 +108,14 @@ fn main() {
 
     let version_path = Path::new(&out_dir).join("version.txt");
     fs::write(&version_path, &version_string).unwrap();
+
+    // Generate man page
+    let man_dir = Path::new("target").join("man");
+    fs::create_dir_all(&man_dir).unwrap();
+    let mut cmd = args::Args::command();
+    cmd = cmd.name("convertis").version(env!("CARGO_PKG_VERSION"));
+    let man = clap_mangen::Man::new(cmd);
+    let mut buffer: Vec<u8> = Default::default();
+    man.render(&mut buffer).unwrap();
+    fs::write(man_dir.join("convertis.1"), buffer).unwrap();
 }

src/args.rs

@@ -15,11 +15,15 @@
 use clap::Parser;
 use std::path::PathBuf;
 
-pub const VERSION: &str = include_str!(concat!(env!("OUT_DIR"), "/version.txt"));
-
 #[derive(Parser, Debug)]
-#[command(version = VERSION, about = "A file converter program.", long_about = None)]
+#[command(about = "A file converter program.", long_about = None)]
 pub struct Args {
+    #[arg(
+        long,
+        help = "List all supported formats.",
+        exclusive = true
+    )]
+    pub list_formats: bool,
     #[arg(
         short = 'v',
         long,
@@ -58,7 +62,7 @@ pub struct Args {
     pub priority: String,
 
     #[arg(help = "The input file path.")]
-    pub input_path: String,
+    pub input_path: Option<String>,
 
     #[arg(help = "The output file path (optional).")]
     pub output_path: Option<String>,

src/main.rs

@@ -21,13 +21,18 @@ pub mod runner;
 include!(concat!(env!("OUT_DIR"), "/plugins_gen.rs"));
 
 use args::Args;
-use clap::Parser;
+use clap::{Parser, CommandFactory, FromArgMatches};
 use std::fs;
 use std::io::{self, IsTerminal, Write};
 use std::process;
 
+pub const VERSION: &str = include_str!(concat!(env!("OUT_DIR"), "/version.txt"));
+
 fn main() {
-    let args = Args::parse();
+    let mut command = Args::command();
+    command = command.version(VERSION);
+    let matches = command.get_matches();
+    let args = Args::from_arg_matches(&matches).expect("Failed to parse arguments");
 
     let level_filter = if args.quiet {
         tracing_subscriber::filter::LevelFilter::OFF
@@ -39,8 +44,35 @@ fn main() {
         .with_max_level(level_filter)
         .init();
 
+    let plugins = get_plugins();
+
+    if args.list_formats {
+        let mut formats: std::collections::HashSet<&str> = std::collections::HashSet::new();
+        for p in &plugins {
+            formats.extend(p.from_formats());
+            formats.extend(p.to_formats());
+        }
+        let mut formats_vec: Vec<_> = formats.into_iter().collect();
+        formats_vec.sort();
+
+        println!("Supported Formats:");
+        for chunk in formats_vec.chunks(6) {
+            let row = chunk.iter().map(|s| format!("{:<10}", s)).collect::<Vec<_>>().join(" ");
+            println!("  {}", row);
+        }
+        return;
+    }
+
+    let input_path = match &args.input_path {
+        Some(path) => path,
+        None => {
+            tracing::error!("Input file path is required unless --list-formats is used.");
+            process::exit(1);
+        }
+    };
+
     // Read input file
-    let input_bytes = match fs::read(&args.input_path) {
+    let input_bytes = match fs::read(input_path) {
         Ok(b) => b,
         Err(e) => {
             tracing::error!("Error reading input file: {}", e);
@@ -48,9 +80,7 @@ fn main() {
         }
     };
 
-    let plugins = get_plugins();
-
-    let from_format = match identifier::identify_format(&args.input_path, &plugins) {
+    let from_format = match identifier::identify_format(input_path, &plugins) {
         Some(f) => f,
         None => {
             tracing::error!("Unknown input format.");