You can change the permissions using the chmod command .
chmod Permission FileName
Some representations of permissions allow you to add permissions by delta, such as octal and "+ x".
This is a sample to change permissions.
# Specify in octal chmod 644 foo.txt chmod 755 dir1 # Add execute permission chmod +x myapp
Recursively change permissions
There is a "-R" option to change permissions recursively.
There is "-R", but the permissions you want to set for directories, normal files, and executable files are different, so if you change them all at once, it will be difficult.
You may also want to give execute permission only to a specific extension.
For example, if you want to give execute permission only to the ".pl" file under the current directory, do as follows.
find * | grep -P '\.pl$' | xargs chmod +x