Rename Multiple Files with Same Digits After Decimal

Question

I have multiple files with names vort-0.01.txt, vort-0.02.txt, ...

vort-0.1.txt ... vort-0.2.txt ... etc.

I want to rename each files with two decimal points i.e. I want to change the name of vort-0.1.txt to vort-0.10.txt and keep vort-0.01.txt as it is.

How can I do that in using bash script?

Thank you for your help.

Accepted Answer

Using the perl-based rename command, then given

$ ls vort*.txt
vort-0.001.txt  vort-0.01.txt  vort-0.1.txt  vort-0.2.txt

then

rename -n 's/(\d+\.\d+)/sprintf "%.2f", $1/e' vort*.txt

will impose 2-digit precision everywhere, as

rename(vort-0.001.txt, vort-0.00.txt)
rename(vort-0.1.txt, vort-0.10.txt)
rename(vort-0.2.txt, vort-0.20.txt)

If you want to rename to a minimum precision i.e. only modify filenames that currently have single-digit precision, then

$ rename -n 's/(\d+\.\d)(?=\D)/sprintf "%.2f", $1/e' vort*.txt
rename(vort-0.1.txt, vort-0.10.txt)
rename(vort-0.2.txt, vort-0.20.txt)

Remove the -n once you are happy that it is doing the right thing.

To do the same thing using bash shell manipulations alone,

for f in vort-?.?.txt; do 
  base=${f%.txt}
  printf -v newname 'vort-%.2f.txt' "${base#vort-}"
  echo mv -- "$f" "$newname"
done

Here, remove the echo after testing.

1 Answer