Setting UNIX Permissions
Please read this entire page before attempting to set your own permissions on our server.

Check the permissions you desire to assign in this top table. The appropriate permission string will be displayed in the numeric field in the bottom table.

Owner (You) Group (Your Group) Other (the world)
Read:
Write:
Execute:
Read:
Write:
Execute:
Read:
Write:
Execute:

Numerical Representation
chmod  filename

UNIX Permissions:

Welcome to our tutorial on UNIX permissions. We've made these instructions in an attempt to show how to set the permissions in your directories (public_html or other).

From the outset, UNIX was designed as a multiuser operating system. This is in start contrast to DOS for example which is definitely a single user operating system. Because multiple people can log onto and use a UNIX system simultaneously, security is a very big concern; even more so in a networked environment like the Internet. For security reasons, UNIX lets you set permissions on your files. These permissions let you determine who you give access to, and what level of access you give.

Who gets access

When it comes to assigning permissions for a file or directory, there are three main categories for which you can assign or deny access:

  • Owner: the owner of a file or directory is usually the creator of that file or directory. If you create or place a file or directory on our server, you are the owner of the file or directory.

  • Group: this is the group to which you belong. Or, more specifically, the group to which the owner of the file belongs. Everyone belongs to a group. When we created your account here at On-Net, we made you a member of a specific group. Some people belong to more that one group.

  • Other: this is the world. "Other" refers to all people other than yourself (owner) and your group.

Permissions: what can be done

In a UNIX environment, there are three main permissions that you can give to a file or directory. These permissions determine what can or cannot be done to the file or directory. The three main types of permissions are:

  • Read: This lets you look at (read) a file. For this reason, the files in your "public_html" directory must be set to "read" for owner, group, and other if you want your web pages to be viewable. If you don't want the world to be able to view a particular file, you had better set permissions for that file so that unwanted people do not have read permissions.

  • Write: This is by far the most dangerous permission. Anyone who has write permission to a file or directory can change or even delete that file or directory. For this reason, we strongly suggest that you do not give write permissions to anyone other than yourself. Certainly do not give write permission to "other".

  • Execute: This permission lets anyone with permission execute a "read" on a directory or execute a program in a directory. If you have a functioning program on our server, it is best to restrict execute permissions to only those who absolutely must have it. This gets confusing, but remember that in order for the contents of a directory to be read, the directory must be executable.

    How Do I Set Permissions?

    You can set the permissions for your files and directories in a number of ways. For those of you familiar with FTP (File Transfer Protocol), many FTP programs allow you set the permissions on files that you transfer up to our server. Usually though, permissions are set using your shell account at the UNIX prompt. Here's how to do it:

    1. Get a "telnet" or terminal emulation program (telnet is preferable), learn how to start it.

      If you are using Windows 95, there is a fine telnet program in the c:\windows directory. It's called "telnet.exe". The host name (computer name) that you will need to telnet to is "sam.on-net.net".

    2. Login using telnet.

      When you start the telnet program and telnet to us, you should see the following prompt on your screen:

      SunOS UNIX (sam)
      login:
      At this prompt, enter your username and hit the <Enter> key on your keyboard. You will then be prompted for your password. Type your password and hit <Enter> on your keyboard. If all is right, a connection will be established and you will be allowed into the system. When you initially connect to our system, you will be in your home directory by default. If successfull, you will see something similar to the following:
      Last login: Wed Jul 2 12:58:27 from johndoe
      SunOS Release 4.1.3_U1 (Sam.noslip) #3: Thu May 29 19:35:41 EST 1997
      $
      Type pwd and hit the <Enter> key on your keybord to show your current directory.

    3. Setting permissions on your home directory.

      In UNIX, permissions are set with the "chmod" command followed by a three-digit numerical string that specifies the permissions and the filemane or directory name for which permissions are to be set. Thus, the syntax for the chmod command is: chmod numericString filename. At the "$" prompt, type cd .. and hit the <Enter> key on your keyboard. This will move you up one directory in the directory structure on our server. At the "$" prompt, type in chmod 711 yourusername and hit the <Enter> key on your keybord. Example: chmod 711 johndoe.

      If you then see only the "$" prompt, you have successfully set the permissions on your home directory.

      Now, type cd yourusername and hit the <Enter> key on your keybord to return to your own home directory. Type pwd and hit the <Enter> key on your keyboard to confirm that you are back in your home directory.

    4. Setting permissions on your public_html directory.

      While in your home directory, type chmod 711 public_html and hit the <Enter> key on your keyboard. If you see only the "$" prompt, you have successfully set the permissions on your public_html directory where all your web files should be.

    5. Setting permissions on your index.html file/web files.

      While in your home directory, type cd public_html and hit the <Enter> key on your keyboard. Type pwd hit the key on your keybord to confirm that you are in your public_html directory. Type chmod -R 644 * and hit the <Enter> key on your keyboard. If you then just see the "$" prompt, you have successfully set the permissions on your main index.html file.

    6. Setting permissions for other files.

      Setting permissions for your other files is done the same way as in step 5 above. Just remember, to set permissions for a particular file, it's best to be in the same directory that the file is in. If you are not sure what to set your permissions as, use our JavaScript Permissions Form. Using this form, just check the priveledges you would like to assign in the first table; the correct permission string will appear in the second table as the numeric value that you should use. Or, type in a three-digit numeric value in the second table to see which permissions are assigned using that value in the top table.

      Setting permissions is extremely important. If you have any questions after reading this tutorial, please don't hesitate to e-mail us at "helpdesk@onet.net" or call us at (317)876-6000 before you make a mistake and jeapordize the security of your files.

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      Tech support may be reached at (317) 876-6000, please leave a voice mail for us after hours. You may reach us by e-mail at helpdesk@on-net.net.