add --dont-fetch

README.md

@@ -15,6 +15,9 @@ depots.
 You can find depot id's for an app on
 [steamdb](https://steamdb.info/app/232250/depots/).
 
+If you only care about knowing the latest manifest, you can pass `--dont-fetch`
+to disable pre-fetching the manifest's data.
+
 ## Output
 
 ```json

src/main.rs

@@ -18,6 +18,8 @@ struct Args {
     /// Only prefetch the listed depot(s)
     #[clap(long)]
     depot: Vec<u32>,
+    #[clap(long)]
+    dont_fetch: bool,
 }
 
 #[tokio::main]
@@ -37,6 +39,10 @@ async fn main() -> MainResult {
             manifest: manifest.gid,
         });
 
+    if args.dont_fetch {
+        let inputs = manifests.collect::<Vec<_>>();
+        serde_json::to_writer_pretty(std::io::stdout(), &inputs)?;
+    } else {
         let outputs = manifests.map(|input| {
             prefetch(&input).map(|hash| ManifestOutput {
                 app_id: input.app_id,
@@ -47,10 +53,12 @@ async fn main() -> MainResult {
         }).collect::<Result<Vec<_>, _>>()?;
 
         serde_json::to_writer_pretty(std::io::stdout(), &outputs)?;
+    }
 
     Ok(())
 }
 
+#[derive(Debug, Serialize)]
 struct ManifestInput {
     app_id: u32,
     depot_id: u32,