Defaults

Directory

775
$ mkdir TEST
$ ls -l TEST
drwxrwxr-x 2 michael 4.0K Sep 27 15:22 TEST

File

664
$ touch TEST.txt
$ ls -l TEST.txt
-rw-rw-r-- 1 michael 0 Sep 27 15:22 TEST.txt

Change

Make executable

$ chmod +x PATH

Set with octet

ugo
$ chmod 775 PATH

Set by column

$ chmod u=rwx,go=rx PATH

Recursive

You can use the -R command, but that is not good if you have a mix of files and directories.

So use find as in blog post.

Reset directories.

$ find . -type d -exec chmod 755 {} \;

Reset files.

$ find . -type f -exec chmod 644 {} \;

Help

Chmod manpage extract.

$ man chmod
NAME
       chmod - change file mode bits

SYNOPSIS
       chmod [OPTION]... MODE[,MODE]... FILE...
       chmod [OPTION]... OCTAL-MODE FILE...
       chmod [OPTION]... --reference=RFILE FILE...

DESCRIPTION
       This  manual  page  documents  the GNU version of chmod.  chmod changes the file mode bits of each given file according to mode, which can be either a symbolic representation of
       changes to make, or an octal number representing the bit pattern for the new mode bits.

       The format of a symbolic mode is [ugoa...][[-+=][perms...]...], where perms is either zero or more letters from the set rwxXst, or a single letter from the  set  ugo.   Multiple
       symbolic modes can be given, separated by commas.

       ...