Rename .gz files according to names in separate txt-file

Question

I want to rename .gz files according to names in separate txt-file. I have a map with .gz files with the names:

trooper10.gz
trooper11.gz 
trooper12.gz
etc.

and I have a separate txt-file with the wanted name(s) in in the first column and the .gz-names in the other column (tab-separated).

B25    trooper10
C76    trooper11
A87_2    trooper12

So the files should be renamed like this

B25.gz
C76.gz
A87_2.gz

I tried

for i in *.gz; do
line=$(grep -x -m 1 -- "${i}" /path_to_txtfile/list_names.txt)

But im not sure how to grep the corresponding column in the txt-file. Since there is many gz-files I want to ask if there is any way to this?

Answer 1

Yes, you just start by reading the file instead of getting the gz files from the file system:

while IFS=$'\t' read -r newName oldName; do
    mv -- "$oldName".gz "$newName.gz"
done < names_file

Answer 2

Could that not just be:

<list_names.txt awk -F'\t' '{printf "%s.gz\0%s.gz\0", $2, $1}' | xargs -r0n2 mv --

Or more efficiently:

perl -F'\t' -lae 'rename "$F[1].gz", $"F[0].gz" or warn "$F[1].gz: $!\n"' list_names.txt