This manualpagedocumentstheGNU version of rm.rm removes each specified file.By default, it does not remove directories.
If the -I or --interactive=once option is given,andtherearemore thanthreefilesorthe-r,-R, or - -recursive are given, then rm prompts
the user for whether to proceed with the entire operation.If the response is not affirmative, the
entire command is aborted. Otherwise,ifa file is unwritable, standard
input is a terminal, and the -f or --forceoptionisnotgiven,orthe-ior--interactive=alwaysoption is given, rm prompts the user for
whether to remove the file.If the response
is not affirmative, the file is skipped.
Which takes one or more arguments. For
each of its arguments it prints to stdout the full path of the executables that
would have been executed when this argument had been entered at the shell
prompt. It does this by searching for an executable or script in the
directories listed in the environment variable PATH using the same algorithm as
This man page is generated from the file
--all, -a Print all matching executables in
PATH, not just the first.
--read-alias, -I Read aliases from
stdin, reporting matching ones on stdout. This is useful in combination with
using an alias for which it self. For example
1.Power on your system. Press the
appropriate key, typically ESC, F12,
or DEL. If a boot menu isn’t available, you’ll need
to adjust the boot sequence in the computer BIOS, which you can then use to
boot directly from your selected media. Set your computer’s BIOS to boot from
the first installation CD or USB drive. Details vary by PC. Make sure your BIOS
saves your changes before you reboot.
You know you're in text mode when the whole screen is black,
showing (in most cases white) characters. A text mode login screen typically
shows some information about the machine you are working on, the name of the
machine and a prompt waiting for you to log in:
RedHat Linux Enterprise Release 5.0 (Psyche)
blast login: _
The login is different from a graphical login, in that you have to
hit the Enter key after providing your user name, because there are no
buttons on the screen that you can click with the mouse. Then you should type your
password, followed by another Enter. You won't see any indication that
you are entering something, not even an asterisk, and you won't see the cursor
move. But this is normal on Linux and is done for security reasons.
When the system has accepted you as a valid user, you may get some
more information, called the message of the day, which can be anything.
Additionally, it is popular on UNIX systems to display a fortune cookie, which
contains some general wise or unwise (this is up to you) thoughts. After that,
you will be given a shell, indicated with the same prompt that you would get in
log in as root
Also in text mode: log in as root only to do setup and
configuration that absolutely requires administrator privileges, such as adding
users, installing software packages, and performing network and other system configuration.
Once you are finished, immediately leave the special account and resume your
work as a non-privileged user. Alternatively, some systems, like Ubuntu, force
you to use sudo, so that you do not need direct access to the
administrative account. Logging out is done by entering the logout command,
followed by Enter. You are successfully disconnected from the system
when you see the login screen again.
While Linux was not meant to be shut off without application of
the proper procedures for halting the system, hitting the power button is
equivalent to starting those procedures on newer systems. However,
powering off an old system without going through the halting process might
cause severe damage! If you want to be sure, always use the Shutdown option
when you log out from the graphical interface, or, when on the login screen
(where you have to give your user name and password) look around for a shutdown
we know how to connect to and disconnect from the system, we're ready for our
This is the default nowadays on most desktop computers. You know
you will connect to the system using graphical mode when you are first asked
for your user name, and then, in a new window, to type your password.
To log in, make sure the mouse pointer is in the login window,
provide your user name and password to the system and click OK or press Enter.
with that root account!
It is generally considered a bad idea to connect (graphically)
using the root user name, the system.
Administrator’s account, since the use of graphics includes
running a lot of extra programs, in root's case with a lot of extra
permissions. To keep all risks as low as possible, use a normal user account to
connect graphically. But there are enough risks to keep this in mind as a
general advice, for all use of the root account: only log in as root when extra
privileges are required.
A lot of
the advantages of Linux are a consequence of Linux' origins, deeply rooted in
UNIX, except for the first advantage, of course:
Linux is free
As in free beer, they say. If you want to spend absolutely
nothing, you don't even have to pay the price of a CD. Linux can be downloaded
in its entirety from the Internet completely for free. No registration fees, no
costs per user, free updates, and freely available source code in case you want
to change the behavior of your system.
Most of all, Linux is free as in free speech
The license commonly used is the GNU Public License (GPL). The
license says that anybody who may want to do so, has the right to change Linux
and eventually to redistribute a changed version, on the one condition that the
code is still available after redistribution. In practice, you are free to grab
a kernel image, for instance to add support for tele transportation machines or
time travel and sell your new code, as long as your customers can still have a
copy of that code.
Linux is difficult to learn depends on the person you're asking. Experienced
UNIX users will say no, because Linux is an ideal operating system for
power-users and programmers, because it has been and is being developed by such
a good programmer can wish for is available: compilers, libraries, development
and debugging tools. These packages come with every standard Linux
distribution. The C-compiler is included for free – as opposed to many UNIX
distributions demanding licensing fees for this tool. All the documentation and
manuals are there, and examples are often included to help you get started in
no time. It feels like UNIX and switching between UNIX and Linux is a natural
early days of Linux, being an expert was kind of required to start using the
system. Those who mastered Linux felt better than the rest of the
"lusers" who hadn't seen the light yet. It was common practice to
tell a beginning user to "RTFM" (read the manuals). While the manuals
were on every system, it was difficult to find the documentation, and even if
someone did, explanations were in such technical terms that the new user became
easily discouraged from learning the system.
Linux-using community started to realize that if Linux was ever to be an
important player on the
Operating system market, there had to
be some serious changes in the accessibility of the system.
beginning of the 90s home PCs were finally powerful enough to run a full blown
UNIX. Linus Torvalds, a young man studying computer science at the University
of Helsinki, thought it would be a good idea to have some sort of freely
available academic version of UNIX, and promptly started to code.
to ask questions, looking for answers and solutions that would help him get
UNIX on his PC. Below is
one of his first posts in comp.os.minix, dating from 1991:
Due to a
project I'm working on (in minix), I'm interested in the posix standard
definition. Could somebody please point me to a (preferably) machine-readable
format of the latest posix rules? Ftp-sites would be nice.
Today Linux has joined the desktop market. Linux developers
concentrated on networking and services in the beginning, and office
applications have been the last barrier to be taken down. We don't like to
admit that Microsoft is ruling this market, so plenty of alternatives have been
started over the last couple of years to make Linux an acceptable choice as a
workstation, providing an easy user interface and MS compatible office applications
like word processors, spreadsheets, presentations and the like.
On the server side, Linux is well-known as a stable and reliable
platform, providing database and trading services for companies like Amazon,
the well-known online bookshop, US Post Office, the German army and many
others. Especially Internet providers and Internet service providers have grown
Prior to installation, the most important factor is your hardware.
Since every Linux distribution contains the basic packages and can be built to
meet almost any requirement (because they all use the Linux kernel), you only
need to consider if the distribution will run on your hardware. LinuxPPC for
example has been made to run on Apple and other PowerPCs and does not run on an
ordinary x86 based PC. LinuxPPC does run on the new Macs, but you can't use it
for some of the older ones with ancient bus technology. Another tricky case is Sun
hardware, which could be an old SPARC CPU or a newer UltraSparc, both requiring
different versions of Linux.
Some Linux distributions are optimized for certain processors,
such as Athlon CPUs, while they will at the same time run decent enough on the
standard 486, 586 and 686 Intel processors. Sometimes distributions for special
CPUs are not as reliable, since they are tested by fewer people.
In 2008, IDC analyst Al Gillen cited a nearly
24 percent annual growth rate for the Linux industry, which puts a $21 billion
2007 technology at $49 billion in 2011. The companies involved in Linux include
industry leaders such as IBM, Fujitsu, Hewlett-Packard, Oracle, Intel, Hitachi,
NEC, and Novell. All have all invested time, talent, and resources to bettering
Linux on their own and through the Linux Foundation.
If Linux is free of cost, how does a Linux
company generate revenue?
Linux is an operating system that is comprised
of many different development languages. A very large percentage of the
distributions' code is written in either the C (52.86%) or C++ (25.56%)
languages. All of the rest of the code falls into single-digit percentages,
with Java, Perl, and Lisp rounding out the rest of the top 5 languages.
The Linux kernel itself has an even more
dominant C presence, with over 95 percent of the kernel's code written in that
language. But other languages make up the kernel as well, making it more
heterogenous than other operating systems.
Linux communities come in two basic forms:
developer and user communities.
One of the most compelling features of Linux
is that it is accessible to developers; anybody with the requisite skills can
improve Linux and influence the direction of its development. Proprietary
products cannot offer this kind of openness, which is a characteristic of the
free software process.
Developer communities can volunteer to
maintain and support whole distributions, such as the Debian or Gentoo
Projects. Novell and Red hat also support community-driven versions of their
products, openSUSE and Fedora, respectively. The improvements to these
community distros are then incorporated into the commercial server and desktop
products from these companies.
The Linux kernel itself is primarily supported
by its developer community as well and is one of the largest and most active
free software projects in existence. A typical three-month kernel development
cycle can involve over 1000 developers working for more than 100 different
companies (or for no company at all).
Code is contributed to the Linux kernel under
a number of licenses, but all code must be compatible with version 2 of the GNU
General Public License (GPLv2), which is the license covering the kernel
distribution as a whole. In practice, that means that all code contributions
are covered either by GPLv2 (with, optionally, language allowing distribution
under later versions of the GPL) or the three-clause BSD license. Any
contributions which are not covered by a compatible license will not be
accepted into the kernel.
Copyright assignments are not required (or
requested) for code contributed to the kernel. All code merged into the
mainline kernel retains its original ownership; as a result, the kernel now has
thousands of owners.