check the file extension in bash code example

Example 1: if file has extension bash

if [[ ${file: -3} == ".gz" ]]

Example 2: bash find files with extension

# syntax
find </path/to/dir> -name '.<extension>'

# example 
find /export/home/jacquesk -name '*.txt'

# This will search in folder-path (including subdirectories) 
# of "/export/home/jacquesk", and will show any files 
# that end in '.txt'