One of the paradigm shifts Windows users (and even some Unix users)
have to get by is often seen in a "How do I do X in Y?" question, for
example "How do I repeat commands in Unix?".
Of course that can be a perfectly legitimate question, but often
the person asking is missing an important concept: Unixish systems
do not tightly bind the user interface to the system. That
particular question is a user interface question, and the answer
is (depending upon how much of an s.o.b. you want to be) "That has
nothing to do with 'Unix'" or "That depends upon what shell you are
using."

For old Unix and Linux hands, the unbinding is obvious: we have choices.
We can choose our shells, our windows managers, even our filesystems.
Windows users have much less choice, especially "out of the box". An
XP system is a tightly bound system of tools - windows work the
way windows work, there's one command line shell, and while there
are three possible file systems, there's no reason to use the older
types unless you are dual booting some ancient Windows or have old
disks that need to be accessed.

So Windows users aren't prepared for choice. The same misunderstandings
apply to naive Unix users who never understood that they had choices:
a csh user suddenly transported to Linux bash may cry "How do I repeat
commands in Linux?", a SCO user accustomed to DEL being his INTR character
will complain "I can't get ping to stop!" (and a Windows user,
accustomed to "ping" quitting by itself, will make the same complaint).
None of them understand that it isn't "Linux" or "OS X" that is conspiring
to confuse them: it's simply default choices that can be easily changed.

For those that arrived here from some Google search, Linux
bash shell repeats commands with 'up arrow' and you'd stop "ping" with
CTRL-C, but those are again defaults and might be different.

Windows users (and the naive Unix users, which might include
many Mac OS X users) need to adjust their view of how things work.
Some time ago I wrote New to Unix. That's helpful, but it doesn't necessarily point your brain in the
direction it needs to go - it's not just substituting one set of
rules for another (slashes vs. backslashes), it's understanding that a lot
of this can be a matter of choice.

How do you know when it's choice and when you are stuck with it? Well,
really, you are almost never "stuck"; whatever you need probably
can be accomplished some way. The idea is to know what's trivial and
what is not, and of course the more you understand about how your
system really works, the easier it is to make that judgment. When
you first have that "Aha!" moment where you realize that your gui
and your shell are just programs that call upon services in the
Unix kernel, you have learned a lot. It may still be hard to
know when something is really "Unix" and when it is not, but
generally you should realize that operating systems themselves
do simple things: they read and write data, and not a lot more.

In other words, the operating system doesn't get involved with complicated
stuff like editing a file: it just reads the bytes some editing program
wants and writes them back to the file system when the editor tells
it to. Most everything in between is up to the program you are
using - that editor of course calls on the OS to get keystrokes
and to send things to your screen, but most of what it does has
little to do with the OS itself: with some adjustments, it could work
quite happily on an entirely different operating system. Even
that business of reading and writing the file system is a bit
outside the operating systems real control: it passes off most
of the responsibility to a file system driver, which is just a
program added on to the base system.. a different program
could be substituted and the system would still work as it always
has.

For the same reasons, your operating system isn't concerned with
legal file names, whether or not you can type both "lc" and "LC",
how you stop a command from running (though actually stopping it
is the operating systems job) or what colors are shown as the
background. I suppose I could give hundreds of other examples,
but it boils down to knowing how things work: if you understand
that your car is out of gas, you don't expect it to start by
hooking up to another car with jumper cables, right? But why
do you know that? Because you have at least a rudimentary understanding
of how cars work. If you did not, you might not realize the
futility of getting a "jump" when your gas tank is empty.

The same is true for operating systems. The more you understand
about how they work, the more you'll understand what you should be
able to control easily.

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