[Techtalk] New to the list...new to linux

[Kai MacTane]

At 9/29/01 08:43 PM , Tianna Thomas wrote:
>OK, I DID IT!  My files have been copied...now I have to figure out how to
>get access to those files to edit them.  I might need help but I'm going to
>TRY to get it on my own.

What you probably want are ls -l, chown, and possibly chmod. "man chown" 
and "man chmod" should tell you all about those two, although you may want 
a bit of help understanding the chmod manual and options. (They're a bit 
confusing at first, unless you're used to thinking in octal...) "man ls" 
won't tell you enough about the -l flag ("flag" is another name for 
"switch"); it simply says:

    -l     use a long listing format

That "long listing format" gives you a wealth of information about each 
file, as follows. First an example of ls -l output:

-rw-rw-r--   1 kmactane kmactane    20355 Nov  6  2000 atm-october
-rw-rw-r--   1 root     root           68 Dec  7  1999 backup-list
drwxrwxr-x   2 kmactane kmactane     1024 Apr 19 14:36 bin/
-rw-rw-r--   1 kmactane kmactane   296970 Apr 30 22:29 bounce.txt
-rwxrwxr-x   1 kmactane kmactane       23 Jul  5  2000 check-gateway*
-rw-rw-r--   1 kmactane kmactane    10262 Jul 31 16:06 codered
-rw-------   1 kmactane kmactane   114688 Oct 11  2000 core
drwxrwxr-x   9 kmactane kmactane     1024 Aug 13 14:44 devel/
-rw-------   1 kmactane kmactane    70757 Jan 14  2000 diary
-rw-rw-r--   1 kmactane kmactane     1032 Jan 26  2000 docfile.gif

The first column is the permissions -- a full explanation of those would 
take a bit, and I'll give it if you ask. The brief explanation is:

If the first character is a "d", the file is a directory; otherwise, it's a 
normal file. (There are many other characters for various types of special 
files, but you hopefully won't encounter those for a bit.) Then there are 
three sets of "rwx" options, one each for the user who owns the file, the 
group that owns the file, and everyone else. r means that 
person/group/whatever can read the file; w means they can write to it, and 
x means they can execute it.

Next comes the number of links the file has, which you can ignore. (Other 
listies: is that right? I use that column so seldom, I'm really not sure 
about that answer's correctness.) Then come the user and group that own the 
file. Then the number of bytes, the last modification time, and finally, 
the file's name.

This listing is actually also using the -F option, which appends a special 
character to directories, symlinks, and executable files: / for 
directories, * for executables, and @ for symlinks.

So, in the above listing, bin and dvel are directories. check-gateway is 
executable (probably some kind of Perl or shell script). core and diary can 
only be read and written by user kmactane. backup-list is owned by root; it 
can be read by anyone, but can only written by root, or by members of the 
root group.

Make sense? So, using ls -l, you can easily find out what user(s) and 
group(s) own the files in a given directory, and then you can use chown to 
change their ownerships (if you have write permission to them in the first 
place).

>Thanks SO MUCH for your help.  Figuring out how to do even that simple
>procedure would have taken me all weekend.  I have to say that I've never
>gotten quite this calibre of assistance from any of my ASP or NT lists.

You're welcome. I know Microsoft keeps trying to say that Linux "isn't 
supported", but it's really not true. Only Microsoft can provide support 
for their systems (if you pay their support fees, and don't mind waiting on 
hold for hours...), but Linux is supported by thousands or even millions of 
users worldwide. (I'm just glad there are finally some questions coming out 
here that I can answer. I'd been feeling bad about getting so much 
assistance from this list without giving anything back yet...)

>I might actually make it through this as long as you guys don't get tired of
>*stupid* questions.

So far, the questions haven't been stupid. Very basic, yes, but that's to 
be expected of newbies. No doubt we will eventually tire of answering 
basic-level questions, but hopefully by then you'll be past those. :) 
(Plus, we've got multiple people here to spread the 
basic-question-answering load around.)

One of the myriad ways in which Unix, Linux, and their associated cultures 
are different from Windows, MacOS, and _their_ associated cultures is that 
there's an expectation that users should not only learn how to use the OS; 
they should also learn how to *learn more* about the OS. Someone earlier 
mentioned that Windows help files are generally not very helpful, and I'd 
agree. Heck, I'd amplify, by saying that Windows help files generally only 
tell you how to perform the most basic tasks, under the most standard 
circumstances -- things that most people should be able to figure out for 
themselves. Unix man pages, OTOH, tell you what *all* the options are; some 
of the more technical ones even tell you something about _exactly_ how a 
particular program, subroutine, or library function performs, so that you 
can figure out what it will do even when given weird or unexpected input.

In short, Unix's various types of docs give you the information you need 
not only to perform everyday tasks, but also to explore, to tweak, and even 
to build on the system. This allows user to become far more empowered in 
the Unix, and especially the open-source Unix, world.

I'm not saying you should go out and learn to program. But consider 
strongly the idea that, as you learn about the basic commands, the 
filesystem structure, and so on, you should also give some effort to 
learning how to learn more. It will help you immeasurably if you intend to 
do much work with Linux.

>Oh yeah, I called my boss...we have a meeting Monday to discuss bringing in
>a consultant.  I want to learn this now, the box and I are at war.

Yee-hah! And it looks like you *do* want to do more work with Linux. 
Congratulations!

I wish you the best of luck.

                                                 --Kai MacTane
----------------------------------------------------------------------
"Playing dead and sweet submission,
  Cracks the whip deadpan on cue."
                                                 --Siouxsie and the
                                                   Banshees,
                                                  "Peek-a-boo"