allow input of "-" to read from STDIN

Author: kyclark

src/bin/mdr-toml.rs

@@ -1,13 +1,14 @@
-use anyhow::Result;
+use anyhow::{anyhow, Result};
 use clap::Parser;
 use mdr::metadata::Meta;
-use std::path::PathBuf;
+use std::{fs, io};
 
 // --------------------------------------------------
 #[derive(Parser, Debug)]
 pub struct Args {
+    /// Input filename or "-" for STDIN
     #[arg()]
-    pub filename: PathBuf,
+    pub filename: String,
 }
 
 // --------------------------------------------------
@@ -20,7 +21,23 @@ fn main() {
 
 // --------------------------------------------------
 fn run(args: Args) -> Result<()> {
-    let meta = Meta::from_file(&args.filename)?;
+    let contents = open(&args.filename)?;
+    let meta = Meta::from_string(&contents)?;
     println!("{}", meta.check().join("\n"));
     Ok(())
 }
+
+// --------------------------------------------------
+fn open(filename: &str) -> Result<String> {
+    match filename {
+        "-" => {
+            let mut contents = vec![];
+            for line in io::stdin().lines() {
+                contents.push(line.unwrap());
+            }
+            Ok(contents.join("\n"))
+        }
+        _ => fs::read_to_string(filename)
+            .map_err(|e| anyhow!(format!("{filename}: {e}"))),
+    }
+}

src/metadata.rs

@@ -119,6 +119,10 @@ impl Meta {
             .map_err(|e| anyhow!(r#"Failed to parse "{}": {e}"#, path.display()))
     }
 
+    pub fn from_string(contents: &str) -> Result<Self> {
+        toml::from_str(&contents).map_err(|e| anyhow!(r#"Failed to parse input: {e}"#))
+    }
+
     pub fn check(&self) -> Vec<String> {
         let mut messages = vec![];
         if let Err(e) = self.validate() {