Linux / UNIX: Change File Permissions Recursively ( conditional )

by on December 27, 2006 · 18 comments· LAST UPDATED September 21, 2011

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How do I recursively change files with 777 permissions to 755 in /home/user/demo directory? I have a number of files in this directory and I need to change permission from 0777 to only if that file has 777 permissions. Is there an easy way out to achieve this?

To change file access permissions you need to use the chmod command.

It has -R or --recursive option that change files and directories recursively. The find command can be used to find files and directories. The chown command can be used to change user and group permission.

chmod Command Example

In this example, you are setting permission to 0755:
$ chmod -R 0755 directoryNameHere
However, if you need to apply conditional file permissions recursively, you need to use combination of the find and chmod command. To find all files in /home/user/demo directory, enter:
$ find /home/user/demo -type f -print
To find all files in /home/user/demo directory with permission 777, enter:
$ find /home/user/demo -type f -perm 777 -print
Finally, apply new permission using the -exec option as follows:
$ find /home/user/demo -type f -perm 777 -print -exec chmod 755 {} \;
To select directories and subdirectories use the following syntax:

$ find /var/www/html -type d -perm 777 -print -exec chmod 755 {} \;

Sample Shell Script To Change Permission Recursively

 
#!/bin/bash
# Purpose: Set correct webserver files and dir permissions
# Author: Vivek Gite < vivek@nixcraft.com >
# This script is released under GPL version 2.0 or above
# Set root permission as follows for the Apache / Lighttpd / Nginx DocumentRoot
# + Dirs/Subdirs: read-only and execute to others
# + Files: read-only permission
# Tested on Debian Linux v3/4/5/6 and RHEL v2/3/4/5/6
# -------------------------------------------------------------------------------------------------
_dir="${1:-.}"
_fperm="0444"
_dperm="0445"
_ugperm="root:root"
_chmod="/bin/chmod"
_chown="/bin/chown"
_find="/usr/bin/find"
_xargs="/usr/bin/xargs"
 
echo "I will change the file permission for webserver dir and files to restrctive read-only mode for \"$_dir\""
read -p "Your current dir is ${PWD}. Are you sure (y / n) ?" ans
if [ "$ans" == "y" ]
then
	echo "Changing file onwership to $_ugperm for $_dir..."
	$_chown -R "${_ugperm}" "$_dir"
 
	echo "Setting $_fperm permission for $_dir directory...."
	$_chmod -R "${_fperm}" "$_dir"
 
	echo "Setting $_dperm permission for $_dir directory...."
	$_find "$_dir" -type d -print0 | $_xargs -0 -I {} $_chmod $_dperm {}
fi
 

You can run this script as follows:
./script /var/www/html/
./script /usr/lib/cgi-bin/

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{ 18 comments… read them below or add one }

1 Thankful guy September 17, 2008 at 7:21 am

Thanks a lot for the tutorial. Now I can change the permission of a folder and its subfolders without affecting files inside. i.e.:

$ find folder_name -type d -exec chmod 775 ‘{}’ \;

Reply

2 Info Gaptek May 26, 2009 at 4:07 am

I found this page by googling.
Thanks for your help!

Reply

3 jay June 21, 2009 at 11:31 am

Thanks for this amazing commands…!

Reply

4 Kiwi Chris August 5, 2009 at 11:52 pm

Hi this was excellent I used what you had here to change my permissions
I changed it a little to work the way I wanted, which was to change all in the path to permissions I wanted, also works for ownership.

Use this method for Chown:

find . /home/admin/data/ -type d -exec chown admin.admin {} \;
find . /home/admin/data/ -type f -exec chown admin.admin {} \;

Public_html

find . /home/admin/public_html/ -type d -exec chmod 755 {} \;
find . /home/admin/public_html/ -type f -exec chmod 644 {} \;

Reply

5 Zilverdistel December 11, 2010 at 11:31 am

Thanks! I used it this way, after changing uid for a user:

find -gid 1000 -exec chown -h :username {} \;

Reply

6 birkopf August 8, 2011 at 11:30 am

Excellent. Finally after weeks of searching this worked like a charm. Using the opportunity:
- Is there a way to search (for example) all files with permission 700 and select all that are NOT 700 ? I mean inverse selection.

Reply

7 sha September 7, 2011 at 4:14 pm

I thank you so much for highlighting this wonderful command.

Reply

8 Birkopf September 8, 2011 at 10:03 am

If you use gnome you can also do graphical way in nautilus. Do as follow:

1) open gconf (for example in terminal or Alt+F2)
2) in gconf-editor under /apps/nautilus/preferences select “show_advanced_permissions”
3) close, open nautilus, right click on folder or file, select permissions and enjoy… :)

Reply

9 Poum November 28, 2011 at 2:14 pm

Thank you, that’s cool.

Reply

10 Andy January 1, 2012 at 4:59 am

Do not do what I did. In a brief moment of aloofness, I happened to mistake “./” with “/.”

The “./” means this directory while the latter “/.” means root… where all the apps are installed…

:(

Reply

11 Çağrı May 11, 2012 at 12:42 pm

Thnx man, that’s a good point : )

Reply

12 Outsourcing Nepal January 3, 2012 at 8:38 am

Still wondering warys to accomplish the task in cuteftp

Reply

13 vonbeau March 25, 2012 at 5:46 am

Great help, thank you.. I rsynced to server with -a [archive] switch and it changed the file permissions so smb didn’t work any longer… Anyway, thank you again.

Reply

14 viraj March 30, 2012 at 10:05 pm

hi all.
Having a great pleasure for the above posted answer,but i have got a doubt that
how would we change the permission for some specific files having only read permission
to both read and execute through shell script.

Reply

15 Francis September 18, 2012 at 2:02 pm

Hey Vivek,

I went trawling the web for an elegant and simple solution to this and decided to write a little script for this myself.

It basically does the recursive chmod but also provides a bit of flexibility for command line options (sets directory and/or file permissions, or exclude both it automatically resets everything to 755-644). It also checks for a few error scenarios.

Check it out:
http://bigfloppydonkeydisk.blogspot.com.au/2012/09/recursively-chmod-only-files-or.html

Hope it helps!

Reply

16 Hari June 14, 2013 at 3:00 pm

Thank you. This really helped me

Reply

17 Engin November 3, 2013 at 6:04 pm

Ty for article, really looking for permissions important.

Reply

18 auchomage April 6, 2014 at 9:29 pm

This has saved me a lot time and trouble. Thank you for sharing this information.

Reply

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