A Bit More on Chmod & Chown

There are a few more things that I would like to introduce when it comes to the chmod and the chown command, one of these things being options that can be passed to reduce the amount of typing the user does in the command line. I'm certain that there are those of us who have had yet to learn how to touch type in QWERTY and even fewer of us who have learned to type in DVORAK. There is such thing as OCTAL NUMBERS that I would like to introduce in this chapter.

Octal Numbers

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With octal numbers:

• They are any number between 0 and 7.
• Each digit in an octal number represents three binary digits.

Now, for further explanation, you lay out a chart like this for better understanding:

Octal	Binary	File Mode
0	000	---
1	001	--x
2	010	-w-
3	011	-wx
4	100	r--
5	101	r-x
6	110	rw-
7	111	rwx

How This Can Be Applied to Chown

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Now, you would use octal numbers as an 'option' rather than an argument when you're making a change to a file, but unlike most options that we have seen, it does not possess a "-" before it. That's okay, different programs might not even contain options and might just have the program itself and yet the use of the program, or command, may vary. For example:

chmod 777 text.txt.

With an ls -l, we'd see that everyone can see, edit, and execute the file called "text".

But what if we don't want to put in that extra typing into the command line to see what the changes made were? Then we use the '-c' [called 'change'] option to print only if there was a change. If you want an output regardless, use the '-v' [called verbose] option.

These same commands can be passed to someone who wants to print the change in a file [if there is one], or just the supposed adjustments made regardless of whether there is an actual change or not.

And Those Two Options Are The Same For Chown

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Simply 'chown -c olduser newuser' where the 'olduser' is the original owner and 'newuser' is the new owner, will print a change only if there is one, but 'chown -v olduser newuser' will print a change regardless.

That's it.

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Thanks for taking the time to read this and be sure to comment if there is anything that you are fuzzy about or that you do not understand. useradd

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userdel

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usermod

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