[SOLVED] How to put a sequential number in the middle of my filenames in Linux

Issue

I have some files in a directory and I want to rename them in such a way they will have sequence.

Original Filenames:

Customer_Branch_Record.20230303.1349.DAT
Customer_Branch_Record.20230303.1356.DAT
Customer_Branch_Record.20230303.1527.DAT

I want to put a sequence 01 02 03 and so on in between the filenames and output below

Customer_Branch_Record.01.20230303.1349.DAT
Customer_Branch_Record.02.20230303.1356.DAT
Customer_Branch_Record.03.20230303.1527.DAT

I tried Bash to rename but it can only rename into a new name and does not use the original details

#!/bin/bash

a=1
for i in Cust*; do
  new=$(printf "Customer_Document_Advices.%02d.txt" "$a") #04 pad to length of 2
  mv -i -- "$i" "$new"
  let a=a+1
done

OUTPUT:

Customer_Document_Advices.02.txt
Customer_Document_Advices.01.txt
Customer_Document_Advices.03.txt

I want to do this in such a way that I can place a sequence in the middle and still retain the original details of the filename.

Solution

You can try;

a=1
while read -r line; do
    echo mv $line $(sed -E "/(\.[^.]*){4,}/ ! s/[^.]*/&.$a/" <<< $line)
    let a+=1
done < <(find /path/to/directory -type f -name 'Cust*' -printf '%f\n')

If the output is as expected, remove the echo to persist the changes

Answered By - HatLess

Answer Checked By - Marie Seifert (WPSolving Admin)