Make commit output the UUID of the commit's snapshot

Cargo.lock

@@ -435,6 +435,7 @@ dependencies = [
  "sudo",
  "tempdir",
  "thiserror",
+ "uuid",
  "walkdir",
  "xattr",
  "xdg",

Cargo.toml

@@ -29,6 +29,7 @@ serde_json = "1.0.96"
 sha2 = "0.10.8"
 sudo = "0.6.0"
 thiserror = "1.0.44"
+uuid = "0.8.2"
 walkdir = "2.3.3"
 xattr = { version = "1.0.0", default-features = false }
 xdg = "2.5.2"

snapshot.output

@@ -228,6 +228,7 @@ Initialized table ./pizza with key: user.toppings
 +./pizza/olive
 + Commit the change with a helpful comment
 + /home/josh/Projects/Ghee/target/debug/ghee commit -m 'Add olive pizza' ./pizza
+0dc9de01-08d3-384d-ac5d-c8e7f7eede8d
 + Make sure the new commit shows up in the log
 + /home/josh/Projects/Ghee/target/debug/ghee log ./pizza
 commit 20c655bb-33da-4a44-9f75-91eb98af8e1a
@@ -249,6 +250,7 @@ m./pizza/olive
 +./pizza/pepperoni
 + Commit the new changes
 + /home/josh/Projects/Ghee/target/debug/ghee commit -m 'Add pepperoni; add details to olive' ./pizza
+ae56b31b-c5e3-c94d-9dc9-4b714635c23e
 + Make sure status and log reflect this
 + /home/josh/Projects/Ghee/target/debug/ghee status ./pizza
 + /home/josh/Projects/Ghee/target/debug/ghee log ./pizza
@@ -504,6 +506,7 @@ Initialized table /home/josh/Projects/Ghee/snapshot/btrfs/pizza with key: user.t
 +./pizza/olive
 + Commit the change with a helpful comment
 + /home/josh/Projects/Ghee/target/debug/ghee commit -m 'Add olive pizza' /home/josh/Projects/Ghee/snapshot/btrfs/pizza
+736136e1-43c0-cd44-81b7-a705e5f58ea0
 + Make sure the new commit shows up in the log
 + /home/josh/Projects/Ghee/target/debug/ghee log /home/josh/Projects/Ghee/snapshot/btrfs/pizza
 commit 05aee894-48f1-3944-b04d-516f026b58c4
@@ -525,6 +528,7 @@ m./pizza/olive
 +./pizza/pepperoni
 + Commit the new changes
 + /home/josh/Projects/Ghee/target/debug/ghee commit -m 'Add pepperoni; add details to olive' /home/josh/Projects/Ghee/snapshot/btrfs/pizza
+90f70b63-0100-e046-b7fc-062029f1e4a7
 + Make sure status and log reflect this
 + /home/josh/Projects/Ghee/target/debug/ghee status /home/josh/Projects/Ghee/snapshot/btrfs/pizza
 + /home/josh/Projects/Ghee/target/debug/ghee log /home/josh/Projects/Ghee/snapshot/btrfs/pizza

src/bin/ghee.rs

@@ -222,8 +222,10 @@ fn run_command(cmd: &Commands) {
             let cur = current_dir().unwrap();
             let dir = dir.as_ref().unwrap_or(&cur);
 
-            commit(dir, message, *verbose)
+            let uuid = commit(dir, message, *verbose)
                 .unwrap_or_else(|e| panic!("Error committing {}: {}", dir.display(), e));
+
+            println!("{}", uuid);
         }
 
         Commands::Log { dir } => {

src/cmd/commit.rs

@@ -8,6 +8,7 @@ use btrfsutil::subvolume::{SnapshotFlags, Subvolume};
 use file_owner::{owner_group, set_owner_group};
 use sudo::escalate_if_needed;
 use thiserror::Error;
+use uuid::Uuid;
 
 use crate::{
     paths::{table_snapshot_path, table_snapshots_path},
@@ -25,8 +26,10 @@ pub enum CommitErr {
 
 /**
  * Commit a table, storing its contents as a BTRFS snapshot
+ *
+ * Returns the commit UUID
  */
-pub fn commit(dir: &PathBuf, message: &Option<String>, verbose: bool) -> Result<()> {
+pub fn commit(dir: &PathBuf, message: &Option<String>, verbose: bool) -> Result<Uuid> {
     escalate_if_needed().map_err(|_e| CommitErr::CouldNotEscalatePrivileges)?;
 
     let subvol = Subvolume::get(dir.as_path()).map_err(|e| {
@@ -84,7 +87,7 @@ pub fn commit(dir: &PathBuf, message: &Option<String>, verbose: bool) -> Result<
         println!("Committed snapshot {}", uuid);
     }
 
-    Ok(())
+    Ok(uuid)
 }
 
 // #[cfg(test)]