dyt-cli: support writing output directly to a file

The nvim integration can continue to use a terminal when the text is
redirected to a file instead of falling back to an emulation with
`jobstart()`.

Author: mathstuf

README.md

@@ -177,6 +177,8 @@ dyt --record | wc -w
 
 Copying to the clipboard can be suppressed with the `--no-clipboard` option.
 
+Output may be redirected to a file with the `--output` flag.
+
 ### Smoke test
 
 Verify your mic works without needing the daemon:

dyt-cli/src/main.rs

@@ -1,3 +1,7 @@
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
 use dyt_cli::{capture, encode, transport};
 
 use anyhow::Result;
@@ -17,6 +21,10 @@ struct Cli {
     /// Suppress copying text to the clipboard.
     #[arg(long)]
     no_clipboard: bool,
+
+    /// Write to an output file. Defaults to stdout.
+    #[arg(long)]
+    output: Option<PathBuf>,
 }
 
 fn main() -> Result<()> {
@@ -43,8 +51,13 @@ fn main() -> Result<()> {
         eprintln!("Copied to clipboard.");
     }
 
-    // Also print to stdout for piping
-    print!("{text}");
+    if let Some(output) = cli.output {
+        let mut fout = File::open(output)?;
+        write!(fout, "{text}")?;
+    } else {
+        // Also print to stdout for piping
+        print!("{text}");
+    }
 
     Ok(())
 }