rst: Allow reading from standard input

Enable the `rst` binary to read a document from standard input. If no
`file` command line argument is given, assume that the document comes
from standard input.

1 files changed, 14 insertions, 3 deletions

diff --git a/rst/src/main.rs b/rst/src/main.rs
index 318bcb6..1418a5e 100644
--- a/rst/src/main.rs
+++ b/rst/src/main.rs
@@ -12,6 +12,8 @@ use rst_renderer::{
 	render_html,
 };
 
+use std::io::{self, Read};
+
 arg_enum! {
 	#[derive(Debug)]
 	#[allow(non_camel_case_types)]
@@ -26,7 +28,7 @@ struct Cli {
 		raw(possible_values = "&Format::variants()", case_insensitive = "true"),
 	)]
 	format: Format,
-	file: String,
+	file: Option<String>,
 	#[structopt(flatten)]
 	verbosity: Verbosity,
 }
@@ -34,9 +36,18 @@ struct Cli {
 fn main() -> CliResult {
 	let args = Cli::from_args();
 	args.verbosity.setup_env_logger("rst")?;
-	
+
+	let content = if let Some(file) = args.file {
+		read_file(file)?
+	} else {
+		let mut stdin = String::new();
+		io::stdin().read_to_string(&mut stdin)?;
+
+		stdin
+	};
+
 	// TODO: somehow make it work without replacing tabs
-	let content = read_file(args.file)?.replace('\t', " ".repeat(8).as_ref());
+	let content = content.replace('\t', " ".repeat(8).as_ref());
 	let document = parse(&content)?;
 	let stdout = std::io::stdout();
 	match args.format {