It's a bad practice because root has rw (read/write) permissions to
every file on the system. So if you accidentally enter an incorrect
command, such as "rm -rf /", you will hose your system.
NB: Do
not enter "rm -rf /". That command means remove (rm)
recursive (r) force (f) from root (/), so it will remove every file and
every directory in your system. There are jerks who have been known
to post that as advice.
Take your typcial beloved Windoze operating system, as an example. Joe
Public buys a computer from Wal-Mart, CompUSA, BestBuy (substitute other
store where employees aren't well-trained) and takes it home. It was setup by
someone in a warehouse, or worse, one of the aforementioned establishment's
sales clerks. There is one user, Administrator, with no password. So whenever
the system is started, he has full rights to every file on the system.
Day 1 -- he gets a free snotmail account, fires up MSN, and starts spamming all the
relatives and friends who gave him their email address (though their conscience
was screaming JUST SAY NO!!!).
Day 2 -- Joe gets an email from some knockout girl in Bolivia who promises to fulfill
his strangest desires (or maybe it was a babe in an IRC chat). He opens the attachment,
or browses to her web page, or accepts the file she offers for download; so he can look
at the merchandise.
BAM!!! Joe gets a trojan, which begins removing files and rearranging his poorly coded in
the first place Windoze operating system.
Day 3 -- Joe gives me a call. Hey, my friend says you're the computer guru. Can you help me?
I've only had this computer three days, and now it won't work. (Needless to say, Joe has no
idea that "it won't work" means next to nothing.)
See the problem? Not only has Joe bought something more powerful than his present level of
knowledge can handle, but he has Administrator rights, which means that when Joe lets the
temptations of life trick him into opening a file he shouldn't, it is allowed to write to
anywhere on his system, including his registry. Effectively, Joe "hosed his box."
Now, if Joe had only a guest account where he logged in, and could not write to the entire
system or "install" software, he'd be protected from himself somewhat.
Slackware, like all true Linux based OSes, has the first line of defense against the ignorance
of us, the users -- it is a true multi-user system. You should only login and start the X server
as a normal user. When you need to do something that requires root privileges, there are easy
ways to su (switch user) to root and get the job done, then logout.
There are many other good links. I'll give you this
FAQ from alt.os.linux.slackware. It has a
lot of information answered that you'll need really soon.
Then you can also check onebuck's
The Slackware LQ Suggestions Links For Linux Slackers!
Please read, and when you get stumped, ask us in the Slackware forum.