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How to CHMOD
by TTG 13 Aug 2005

In various ReadMe files for hacks on Vbulletin.org one may see instructions such as CHMOD 777 a specific file or folder.

Permissions (Or CHMODs as the Linux term) is just the Linux way of assigning "who is allowed to do what".

First you will need to get yourself a good FTP client like CuteFTP or WS_FTP (they allow permissions/CHMODs visually) although you can use SSH and type in commands for CHMODding files and folders manually. For CuteFTP and FTP Pro you simply need to right-click the uploaded file or folder in the remote window and click Properties/CHMOD. You should see a box where you can type a number and a a bunch of tick boxes near it.

A CHMOD is a number, it references reading, writing, execution and group access of a file or folder.

In these three digit CHMOD numbers the first digit indicates the permissions for the owner, the second is the permissions for other members of the same "group" as the owner and third is the permissions for "others", aka the public at large.

You might also find permissions specified in rwx format (r= Read, w= Write, x =eXecute), ex: 600 = -rw-rw-rw-

In the three-digit number format the individual numbers are derived by adding up the permissions with 1=execute, 2=write and 4=read (read, write and execute = 4+2+1 -> 7)

0 = no permissions (---)
1 = execute only (--x)
2 = write only (-w-)
3 = write and execute (-wx)
4 = read only (r--)
5 = read and execute (r-x)
6 = read and write (rw-)
7 = read, write and execute (rwx)
644 (-rw-r--r--) = "I don't mind if other people can read this file, however only I should be able to run or write to/edit it"

755 (-rwxr-xr-x) = "I don't mind if other people can read or run this file, however only I should be able to write to/edit it"

777 (-rwxrwxrwx) = "Anybody can do anything they want (read, run, modify) with this file"

Permissions can be modified in a number of ways:

Using an FTP client such as WS_FTP LE or CuteFTP
Using the CHMOD command in a shell (SSH) session
Using your host's website control panel

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