Renaming directories with specific extensions

Question

An extension to the previous question that I asked: Rename an alphanumeric file

I have a directory that has subdirectories with an extension of *_upstream:

DHX30_vs_Control18.txt_events_without_u2af1_srsf2_altexons_upstream
GEMIN5_vs_Control19.txt_events_without_u2af1_srsf2_altexons_upstream

I want to rename them by removing everything after first '_' such that it becomes something like

DHX30
GEMIN5

Answer 1

for dir in ./*_*_upstream/
do 
  mv -- "$dir" "${dir%%_*}"
done

The above loop picks up every directory (the trailing slash does this) in the current directory that matches the pattern: "(something) underscore (something) underscore upstream". It then renames those directories by using parameter expansion to remove the longest match of: "underscore (anything)", which removes everything from-and-after the first underscore.

For example:

Setup:

mkdir DHX30_foo_upstream
mkdir GEMIN5_vs_Cblah_upstream
touch DX31_foo_upstream

Result:

$ tree
.
├── DHX30
├── DX31_foo_upstream
└── GEMIN5

2 directories, 1 file

Answer 2

If on Linux:

rename -v 's/_.*//' *_upstream/