Perform an action in every sub-directory using Bash

I am working on a script that needs to perform an action in every sub-directory of a specific folder.

What is the most efficient way to write that?

A version that avoids creating a sub-process:

for D in *; do
    if [ -d "${D}" ]; then
        echo "${D}"   # your processing here
    fi
done

Or, if your action is a single command, this is more concise:

for D in *; do [ -d "${D}" ] && my_command; done

Or an even more concise version (thanks @enzotib). Note that in this version each value of D will have a trailing slash:

for D in */; do my_command; done

for D in `find . -type d`
do
    //Do whatever you need with D
done

The simplest non recursive way is:

for d in */; do
    echo "$d"
done

The / at the end tells, use directories only.

There is no need for

• find
• awk
• ...

Use find command.

In GNU find, you can use -execdir parameter:

find . -type d -execdir realpath "{}" ';'

or by using -exec parameter:

find . -type d -exec sh -c 'cd -P "$0" && pwd -P' {} \;

or with xargs command:

find . -type d -print0 | xargs -0 -L1 sh -c 'cd "$0" && pwd && echo Do stuff'

---

Or using for loop:

for d in */; { echo "$d"; }

^{For recursivity try extended globbing (**/) instead (enable by: shopt -s extglob).}

---

For more examples, see: How to go to each directory and execute a command? at SO

Handy one-liners

for D in *; do echo "$D"; done
for D in *; do find "$D" -type d; done ### Option A

find * -type d ### Option B

Option A is correct for folders with spaces in between. Also, generally faster since it doesn't print each word in a folder name as a separate entity.

# Option A
$ time for D in ./big_dir/*; do find "$D" -type d > /dev/null; done
real	0m0.327s
user	0m0.084s
sys	    0m0.236s

# Option B
$ time for D in `find ./big_dir/* -type d`; do echo "$D" > /dev/null; done
real	0m0.787s
user	0m0.484s
sys	    0m0.308s

find . -type d -print0 | xargs -0 -n 1 my_command

This will create a subshell (which means that variable values will be lost when the while loop exits):

find . -type d | while read -r dir
do
    something
done

This won't:

while read -r dir
do
    something
done < <(find . -type d)

Either one will work if there are spaces in directory names.

the accepted answer will break on white spaces if the directory names have them, and the preferred syntax is $() for bash/ksh. Use GNU find -exec option with +; eg

find .... -exec mycommand +; #this is same as passing to xargs

or use a while loop

find .... | while read -r D
do
    # use variable `D` or whatever variable name you defined instead here
done 

You could try:

#!/bin/bash
### $1 == the first args to this script
### usage: script.sh /path/to/dir/

for f in `find . -maxdepth 1 -mindepth 1 -type d`; do
  cd "$f"
  <your job here>
done

or similar...

Explanation:

find . -maxdepth 1 -mindepth 1 -type d : Only find directories with a maximum recursive depth of 1 (only the subdirectories of $1) and minimum depth of 1 (excludes current folder .)