Virtual Private Server User Guide

Internet and UNIX Basics

Each possible combination of permissions for a set can be represented by a 

numeric (octal representation of a binary) value, 0 7, like so:

Value  

Permission  

Directory 

Listing  

0 

 No read, no write, no 

execute 

1  

 No read, no write, execute 

  x  

2  

 No read, write, no execute 

 w  

3  

 No read, write, execute 

 wx 

4  

 Read, no write, no execute 

r   

5  

 Read, no write, execute 

r x 

6  

 Read, write, no execute 

rw  

7  

 Read, write, execute 

rwx 

A full set of permissions is then represented by a three digit number; for example, 

664 corresponds to the following file permissions: 

 rw rw r  

Recall that the first character denotes the type of resource, which in this case is a 

file ( ).

Following are some of the more common chmod numbers and their corresponding 

permission sets:

chmod 557 =   r xr xrwx

chmod 600 =   rw       

chmod 644 =   rw r  r  

chmod 664 =   rw rw r  

chmod 700 =   rwx      

chmod 755 =   rwxr xr x

chmod 775 =   rwxrwxr x

Technical Training Department

August 2004

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