Linux change permissions conditionally

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 {} \;

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