feat(cli): print completion scripts and the man page to stdout

`completions install` writes into a home directory, which a package
build does not have. `completions print <shell>` and `man` give it the
files to put under /usr/share instead.

soulseek-rs/src/SKILL.md

@@ -236,6 +236,9 @@ this skill file into the local agent directories, or remove it: `agent`,
 completion script where bash, zsh, or fish looks for it, or take it back
 again: `shell`, `path`, `action`. For a human at a prompt, not for you.
 
+**`completions print <shell>`** and **`man`** — the completion script or the
+man page on stdout, raw rather than records. For whoever builds a package.
+
 ## Idioms
 
 ```bash

soulseek-rs/src/cli.rs

@@ -249,6 +249,9 @@ pub enum Commands {
     /// Tab completion for bash, zsh, and fish
     #[command(subcommand)]
     Completions(CompletionsCommand),
+
+    /// Print the man page to stdout, for packaging
+    Man,
 }
 
 #[derive(Args, Debug, Default)]
@@ -315,6 +318,12 @@ pub enum CompletionsCommand {
 
     /// Remove the completion script again
     Uninstall(CompletionsArgs),
+
+    /// Print the completion script to stdout, for packaging
+    Print {
+        #[arg(value_enum)]
+        shell: Shell,
+    },
 }
 
 #[derive(Args, Debug)]

soulseek-rs/src/commands/completions.rs

@@ -8,10 +8,10 @@
 
 use super::{unwritable, xdg};
 use crate::cli::{Cli, CompletionsArgs, CompletionsCommand, Shell};
-use crate::output::{CliError, CliResult, CompletionRecord, Out};
+use crate::output::{CliError, CliResult, CompletionRecord, Exit, Out};
 use clap::CommandFactory;
 use directories::UserDirs;
-use std::io::Write;
+use std::io::{ErrorKind, Write};
 use std::path::{Path, PathBuf};
 
 /// The command being completed, and the file name the scripts are written as.
@@ -65,6 +65,27 @@ pub fn run(out: &Out, command: &CompletionsCommand) -> CliResult {
     match command {
         CompletionsCommand::Install(args) => install(out, &targets(args)?),
         CompletionsCommand::Uninstall(args) => uninstall(out, &targets(args)?),
+        CompletionsCommand::Print { shell } => print(&script(*shell)),
+    }
+}
+
+pub fn man() -> CliResult {
+    let mut page = Vec::new();
+    clap_mangen::Man::new(Cli::command().about("Soulseek client in Rust"))
+        .render(&mut page)
+        .expect("a Vec accepts every write");
+    print(&page)
+}
+
+fn print(bytes: &[u8]) -> CliResult {
+    match std::io::stdout().write_all(bytes) {
+        Err(error) if error.kind() != ErrorKind::BrokenPipe => {
+            Err(CliError::new(
+                Exit::Failure,
+                format!("cannot write stdout: {error}"),
+            ))
+        }
+        _ => Ok(()),
     }
 }
 

soulseek-rs/src/commands/mod.rs

@@ -330,7 +330,8 @@ fn dispatch(ctx: &Ctx, command: Commands) -> CliResult {
         | Commands::Config(_)
         | Commands::Shares(_)
         | Commands::Skills(_)
-        | Commands::Completions(_) => {
+        | Commands::Completions(_)
+        | Commands::Man => {
             Err(CliError::usage("handled without a session; see main::run"))
         }
     }

soulseek-rs/src/run.rs

@@ -35,6 +35,14 @@ pub fn run(mut cli: Cli, out: &Out) -> CliResult {
         }
     }
 
+    match &cli.command {
+        Some(Commands::Completions(command)) => {
+            return crate::commands::completions::run(out, command);
+        }
+        Some(Commands::Man) => return crate::commands::completions::man(),
+        _ => {}
+    }
+
     let config_path = config_path(&cli);
     let file_config = match &config_path {
         Some(path) => crate::persist::config::FileConfig::load(path)
@@ -84,9 +92,6 @@ pub fn run(mut cli: Cli, out: &Out) -> CliResult {
                 resolved.username.as_deref(),
             );
         }
-        Commands::Completions(ref command) => {
-            return crate::commands::completions::run(out, command);
-        }
         Commands::Config(ConfigCommand::Path) => {
             return crate::commands::settings::config_path(out, &store);
         }