b3sum: add --tag

1 files changed, 16 insertions, 0 deletions

diff --git a/b3sum/src/main.rs b/b3sum/src/main.rs
index baa6b6c..b10cff8 100644
--- a/b3sum/src/main.rs
+++ b/b3sum/src/main.rs
@@ -16,6 +16,7 @@ const KEYED_ARG: &str = "keyed";
 const LENGTH_ARG: &str = "length";
 const NO_NAMES_ARG: &str = "no_names";
 const RAW_ARG: &str = "raw";
+const TAG_ARG: &str = "tag";
 const CHECK_ARG: &str = "check";
 
 #[derive(Parser)]
@@ -72,6 +73,10 @@ struct Inner {
     #[arg(long)]
     raw: bool,
 
+    /// Prefix output with `BLAKE3 (...) =`
+    #[arg(long)]
+    tag: bool,
+
     /// Read BLAKE3 sums from the [FILE]s and check them
     #[arg(
         short,
@@ -80,6 +85,7 @@ struct Inner {
         conflicts_with(KEYED_ARG),
         conflicts_with(LENGTH_ARG),
         conflicts_with(RAW_ARG),
+        conflicts_with(TAG_ARG),
         conflicts_with(NO_NAMES_ARG)
     )]
     check: bool,
@@ -138,6 +144,10 @@ impl Args {
         self.inner.raw
     }
 
+    fn tag(&self) -> bool {
+        self.inner.tag
+    }
+
     fn no_mmap(&self) -> bool {
         self.inner.no_mmap
     }
@@ -393,6 +403,12 @@ fn hash_one_input(path: &Path, args: &Args) -> Result<()> {
     if is_escaped {
         print!("\\");
     }
+    if args.tag() {
+        print!("BLAKE3 ({}) = ", filepath_string);
+        write_hex_output(output, args)?;
+        println!();
+        return Ok(());
+    }
     write_hex_output(output, args)?;
     println!("  {}", filepath_string);
     Ok(())