New sq command to quote input

Cargo.toml

@@ -1,3 +1,6 @@
+[workspace]
+members = ["cli", "."]
+
 [package]
 authors = ["Gavin Panella <gavin@allenap.me>"]
 categories = ["encoding", "filesystem"]

cli/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "shell-quote-cli"
+version = "0.1.0"
+edition = "2021"
+
+[[bin]]
+path = "src/main.rs"
+name = "sq"
+
+[dependencies]
+shell-quote = { path = ".." }
+
+[dependencies.clap]
+version = "=4.5.9"
+features = ["derive", "env", "wrap_help"]

cli/src/main.rs

@@ -0,0 +1,36 @@
+use std::io::{self, IsTerminal, Read, Write};
+
+use shell_quote::{Bash, Fish, Sh};
+
+mod options;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let options = <options::Options as clap::Parser>::parse();
+    let quoted: Vec<u8> = if options.command.is_empty() && !io::stdin().is_terminal() {
+        let mut buf = Vec::new();
+        io::stdin().read_to_end(&mut buf)?;
+        match options.shell {
+            options::Shell::Bash => Bash::quote_vec(&buf),
+            options::Shell::Fish => Fish::quote_vec(&buf),
+            options::Shell::Sh => Sh::quote_vec(&buf),
+        }
+    } else {
+        options
+            .command
+            .iter()
+            .fold(Vec::<u8>::new(), |mut acc, arg| {
+                if !acc.is_empty() {
+                    acc.push(b' ');
+                }
+                match options.shell {
+                    options::Shell::Bash => Bash::quote_into_vec(arg, &mut acc),
+                    options::Shell::Fish => Fish::quote_into_vec(arg, &mut acc),
+                    options::Shell::Sh => Sh::quote_into_vec(arg, &mut acc),
+                };
+                acc
+            })
+    };
+    io::stdout().write_all(&quoted)?;
+
+    Ok(())
+}

cli/src/options.rs

@@ -0,0 +1,35 @@
+use std::ffi::OsString;
+
+use clap::{command, Parser, ValueEnum, ValueHint};
+
+#[derive(Parser, Debug)]
+#[command(
+    author, version, about, long_about = None, max_term_width = 80,
+)]
+pub struct Options {
+    #[arg(
+        short = 's',
+        long = "shell",
+        help = "The shell for which to quote arguments.",
+        value_hint = ValueHint::ExecutablePath,
+        value_enum,
+        env = "SHELL",
+    )]
+    pub shell: Shell,
+
+    #[arg(
+        help = "The arguments to quote. When none are provided, reads from stdin.",
+        trailing_var_arg = true,
+        allow_hyphen_values = true
+    )]
+    pub command: Vec<OsString>,
+}
+
+#[derive(Debug, Clone, ValueEnum)]
+pub enum Shell {
+    #[value(alias = "zsh")]
+    Bash,
+    Fish,
+    #[value(alias = "dash")]
+    Sh,
+}