Posts Tagged ‘Permissions’

Linux permissions demystified

April 22, 2011 by flibs. 6 comments

I have seen a large number of questions on Super User recently all around the same topic of Linux and Unix file permissions. For example:

unix file permissions

File permissions in UNIX are frequently specified as an octal number. Why is octal the preferred base for this purpose?

… and …

Linux file permissions

I own a particular file on a Linux system. I would like to give 2 groups (accounting, shipping) read access and only read access, and 3 users(Mike, Raj and Wally) write access and only write access. How can I accomplish this?

In a world of Windows where file permissions can be granted on a per-user basis, Linux and Unix permissions seem to be very hokey and restricted.

Well, let me tell you, they’re not.  For such a seemingly basic arrangement they are an incredibly powerful tool.

Most people forget that to do anything even remotely fancy with permissions in Linux you really have to couple them with groups.  And you really can do some fancy things with them!

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