Hello Reader....
The article is to give you knowledge about the basic
commands of unix that particularly used in the unix
based operating system.
commands of unix that particularly used in the unix
based operating system.
The article is very
interesting and helps you to all in
learning Unix/linux based operating system.
learning Unix/linux based operating system.
Note: Some commands may be differ/change according
to your operating.
to your operating.
Location:
(1) ls ---> lists your files
(2) ls -l ---> lists your files in 'long format', which contains
lots of useful information, e.g. the exact size of the file,
who owns the file and who has the right to look at it,
and when it was last modified.
(2) ls -l ---> lists your files in 'long format', which contains
lots of useful information, e.g. the exact size of the file,
who owns the file and who has the right to look at it,
and when it was last modified.
(3) ls -a ---> lists all files, including the ones whose file
names begin in a dot, which you do not always want to see.
There are many more options, for example to list files by
size, by date, recursively etc.
(1) more filename ---> shows the first part of a file, just as
much as will fit on one screen. Just hit the space bar to see
more or q to quit. You can use /pattern to search for a pattern.
(2) emacs filename ---> is an editor that lets you create and
edit a file. See the emacs page.
(3) mv filename1 filename2 ---> moves a file (i.e. gives it a
different name, or
moves it into a different directory.
(4) cp filename1 filename2 ---> copies a file.
(5) rm filename ---> removes a file. It is wise to use the option
rm -i, which will ask you for confirmation before actually
deleting anything. You can make this your default by making
an alias in your .cshrc file.
(4) cp filename1 filename2 ---> copies a file.
(5) rm filename ---> removes a file. It is wise to use the option
rm -i, which will ask you for confirmation before actually
deleting anything. You can make this your default by making
an alias in your .cshrc file.
(6) diff filename1 filename2 ---> compares files, and shows
where they differ.
(7) wc filename ---> tells you how many lines, words, and
characters there are
in a file.
(8) chmod options filename ---> lets you change the read,
write, and execute permissions on your files. The default is
that only you can look at them and change them, but you may
sometimes want to change these permissions. For example,
chmod o+r filename will make the file readable for everyone,
and chmod o-r filename will make it unreadable for others
again. Note that for someone to be able to actually look at the
file the directories it is in need to be at
least executable. See help protection for more details.
File Compression:
(1) gzip filename ---> compresses files, so that they take up
much less space. Usually text files compress to about half
their original size, but it depends very much on the size of
the file and the nature of the contents. There are other tools
for this purpose, too
File Compression:
(1) gzip filename ---> compresses files, so that they take up
much less space. Usually text files compress to about half
their original size, but it depends very much on the size of
the file and the nature of the contents. There are other tools
for this purpose, too
(e.g. compress), but gzip usually gives the
highest compression
rate. Gzip produces files with the ending '.gz' appended to
the
original filename.
(2) gunzip filename ---> uncompresses files compressed by gzip.
(3) gzcat filename ---> lets you look at a gzipped file without
actually having
to gunzip it (same as gunzip -c). You can even
print it directly, using gzcat
filename | lpr.
Printing:
(1) lpr filename ---> print. Use the -P option to specify the
printer name if you want to use a printer other than your
default printer.
For example, if you
want to print double-sided, use 'lpr -Pvalkyr-
d', or if you're at CSLI, you may
want to use 'lpr -Pcord115-d'.
See 'help printers' for more information about
printers and their
locations.
(2)
lpq ---> check out the printer queue, e.g. to get the number
needed for
removal, or to see how many other files will be
printed before yours will come out.
printed before yours will come out.
(3) lprm jobnumber ---> remove something from the printer
queue. You can find
the job number by using lpq. Theoretically
you also have to specify a printer
name, but this isn't necessary
as long as you use your default printer in the department.
as long as you use your default printer in the department.
(4) genscript ---> converts plain text files into postscript for
printing, and
gives you some options for formatting. Consider
making an alias like alias ecop
'genscript -2 -r !* | lpr -h -
Pvalkyr' to print two pages on one piece of
paper.
(5) dvips filename ---> print .dvi files (i.e. files produced by
LaTeX). You can
use dviselect to print only selected pages.
See the LaTeX page for more information about how to save
paper when printing drafts.
See the LaTeX page for more information about how to save
paper when printing drafts.
Directories:
Directories, like folders on a Macintosh, are used to group
files together in a hierarchical structure.
(1) mkdir dirname ---> make a new directory
(2) cd dirname ---> change directory. You basically 'go' to
another directory,
and you will see the files in that directory
when you do 'ls'. You always start out in your 'home directory',
and you can get back there by typing 'cd' without arguments.
'cd ..' will get you one level up from your current position. You
don't have to walk along step by step - you can make big leaps
or avoid walking around by specifying pathnames.
when you do 'ls'. You always start out in your 'home directory',
and you can get back there by typing 'cd' without arguments.
'cd ..' will get you one level up from your current position. You
don't have to walk along step by step - you can make big leaps
or avoid walking around by specifying pathnames.
(3)pwd ---> tells you where you currently are.
Finding things:
(1) ff ---> find files anywhere on the system. This can be
extremely useful if
you've forgotten in which directory you
put a file, but do remember the name. In fact, if you use ff -p
you don't even need the full name, just the beginning. This
can also be useful for finding other things on the system e.g.
documentation.
put a file, but do remember the name. In fact, if you use ff -p
you don't even need the full name, just the beginning. This
can also be useful for finding other things on the system e.g.
documentation.
(2)
grep string filename(s) ---> looks for the string in the files.
This can be
useful a lot of purposes, e.g. finding the right file
among many, figuring out
which is the right version of
something,
something,
and even doing serious corpus work.
grep comes in several
varieties (grep, egrep, and fgrep) and has a lot of very
flexible
options. Check out the man pages if this sounds good to you.
About other people:
(1) w ---> tells you who's logged in, and what they're doing.
Especially useful:
the 'idle' part. This allows you to see
whether they're actually sitting there typing away at their
keyboards right at the moment.
whether they're actually sitting there typing away at their
keyboards right at the moment.
(2) who ---> tells you who's logged on, and where they're
coming from. Useful if you're looking for someone who's
actually physically in the same building as you, or in some
other particular location.
(3) finger username ---> gives you lots of information about
that user, e.g. when they last read their mail and whether
they're logged in. Often people put other practical information,
such as phone numbers and addresses, in a file called .plan.
This information is also displayed by 'finger'.
(4) last -1 username ---> tells you when the user last logged on
and off and
from where. Without any options, last will give
you a list of everyone's logins.
you a list of everyone's logins.
(5) talk username ---> lets you have a (typed) conversation
with another user
(6) write username ---> lets you exchange one-line messages with
another user
(7) elm ---> lets you send e-mail messages to people around the
world (and, of
course, read them). It's not the only mailer you
can use, but the one we recommend. See the elm page, and find
out about the departmental mailing lists (which you can also
find in /user/linguistics/helpfile).
can use, but the one we recommend. See the elm page, and find
out about the departmental mailing lists (which you can also
find in /user/linguistics/helpfile).
About your (electronic) self:
(1) whoami ---> returns your username. Sounds useless, but isn't.
You may need
to find out who it is who forgot to log out
somewhere, and make sure *you* have
logged out.
(2) finger & .plan files --->of course you can finger yourself, too.
(2) finger & .plan files --->of course you can finger yourself, too.
That
can be useful e.g. as a quick check whether you got new mail.
Try to create a
useful .plan file soon. Look at other people's .plan
files for ideas. The file
needs to be readable for everyone in order
to be visible through 'finger'. Do
'chmod a+r .plan' if necessary.
You should realize that this information is
accessible from
anywhere in the world, not just to other people on turing.
(3)
passwd ---> lets you change your password, which you should
do regularly (at
least once a year). See the LRB guide
and/or look at help password.
and/or look at help password.
(4) ps -u yourusername ---> lists your processes. Contains lots of
information
about them, including the process ID, which you need
if you have to kill a
process. Normally, when you have been
kicked out of a dialin session or have
otherwise managed to get
yourself disconnected abruptly, this list will contain
the processes
you need to kill. Those may include the shell (tcsh or whatever
you're using), and anything you were running, for example emacs
or elm. Be
careful not to kill your current shell - the one with the
number closer to the
one of the ps command you're currently
running. But if it happens, don't panic.
Just try again Smile If
you're using an X-display you may have to kill some X
processes
before you can start them again. These will show only when you
use ps
-efl, because they're root processes.
(5) kill PID ---> kills (ends) the processes with the ID you gave.
This works
only for your own processes, of course. Get the ID by
using ps. If the process
doesn't 'die' properly, use the option -9.
But attempt without that option
first, because it doesn't give the
process a chance to finish possibly
important business before
dying. You may need to kill processes for example if
your modem
connection was interrupted and you didn't get logged out
properly, which sometimes happens.
(6) quota -v ---> show what your disk quota is (i.e. how much
space you have to
store files), how much you're actually using,
and in case you've exceeded your
quota (which you'll be given an
automatic warning about by the system) how much
time you have
left to sort them out (by deleting or gzipping some, or moving
them to your own computer).
(7) du filename ---> shows the disk usage of the files and
directories in
filename (without argument the current
directory is used). du -s gives only a total.
directory is used). du -s gives only a total.
(8) last yourusername ---> lists your last logins. Can be a useful
memory aid
for when you were where, how long you've been
working for, and keeping track of
your phone bill if you're
making a non-local phone call for dialling in.
Connecting to the outside world:
(1) nn ---> allows you to read news. It will first let you read
the news local to turing, and then the remote news. If you
want to read only the local or remote news, you can use nnl
or nnr, respectively. To learn more about nn type nn, then
tty{:man}, then tty{=.*}, then tty{Z}, then hit the space bar
to step through the manual. Or look at the man page.
Or check out the hypertext nn
FAQ
- probably the easiest and most fun way to go.
(2) rlogin hostname ---> lets you connect to a remote host
(3) telnet hostname ---> also lets you connect to a remote host.
Use rlogin whenever possible.
(4) ftp hostname ---> lets you download files from a
remote host which is set up as an ftp-server. This is a
common method for exchanging academic papers and
drafts. If you need to make a paper of yours available
in this way, you can (temporarily) put a copy in
/user/ftp/pub/TMP. For more permanent solutions, ask
Emma. The most important commands within ftp are get for
getting files from
the remote machine, and put for putting
them there (mget and mput let you specify more than one
file at once).
them there (mget and mput let you specify more than one
file at once).
Sounds straightforward, but be sure not to confuse
the two,
especially when your physical location doesn't correspond
to the direction of the ftp connection you're making. ftp just
overwrites files with the same filename. If you're transferring
anything other han ASCII text, use binary mode.
to the direction of the ftp connection you're making. ftp just
overwrites files with the same filename. If you're transferring
anything other han ASCII text, use binary mode.
(5) lynx ---> lets you browse the web from an ordinary
terminal. Of course you can see only the text, not the
pictures. You can type any URL as an argument to the G
command. When you're doing this from any Stanford host
you can leave out the .stanford.edu
part of the URL when connecting to Stanford URLs. Type
H at any time to learn more about lynx, and Q to exit.
H at any time to learn more about lynx, and Q to exit.
Miscellaneous tools:
(1) webster word ---> looks up the word in an electronic
version of Webster's dictionary and returns the definition(s).
(2) date ---> shows the current date and time.
(3) cal ---> shows a calendar of the current month. Use e.g.,
'cal 10 1995' to get that for October 95, or 'cal 1995' to get
the whole year.
I hope you all enjoyed the article about basic unix command
and hope helps you all to make better in Unix/ Linux
operating system.