sjl at alephnull in ~/scratch/tmp ><((°> diff -U0 (ls -1 | psub) (ls -1 | grep -v foo | psub) --- /tmp/.psub.cIcXKeQj3O 2019-10-10 10:21:58.940444840 -0400 +++ /tmp/.psub.7W6mBnxcQD 2019-10-10 10:21:58.952444799 -0400 @@ -3 +2,0 @@ -foo