File permission HOWTO

Numeric

 Value in      Corresponding
     Mode      Permission

               Other users not in the file's group:
        1      Execute
        2      Write
        4      Read

               Other users in the file's group:
       10      Execute
       20      Write
       40      Read

               The file's owner:
      100      Execute
      200      Write
      400      Read

               Special permissions:
     1000      Save text image on swap device
     2000      Set group ID on execution
     4000      Set user ID on execution