[SOLVED] How to go to each directory and execute a command?

Issue

How do I write a bash script that goes through each directory inside a parent_directory and executes a command in each directory.

The directory structure is as follows:

parent_directory (name could be anything - doesnt follow a pattern)

• 001 (directory names follow this pattern)
  • 0001.txt (filenames follow this pattern)
  • 0002.txt
  • 0003.txt
• 002
  • 0001.txt
  • 0002.txt
  • 0003.txt
  • 0004.txt
• 003
  • 0001.txt

the number of directories is unknown.

Solution

You can do the following, when your current directory is parent_directory:

for d in [0-9][0-9][0-9]
do
    ( cd "$d" && your-command-here )
done

The ( and ) create a subshell, so the current directory isn't changed in the main script.

Answered By - Mark Longair