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UNIX
Command
Question | Answer |
---|---|
Name the command that is used to list the files? | Is |
What is "Is -I" command used for? | It lists your files in a '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. |
This command lists all files, including the ones whose filenames 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. | Is -a |
What is "more filenameā command used for? | It shows the first part of a file, just as much as will fit on one screen. |
It is an editor that lets you create and edit a file. | emacs filename |
mv filename1 filename2 is used for? | It helps in moving the file (i.e. gives it a different name, or moves it into a different directory |
Copies a file. | cp filename1 filename2 |
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. | rm filename1 |
Compares files, and shows where they differ | diff filename1 filename2 |
It tells you how many lines, words, and characters there are in a file | wc filename |
It 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. | chmod options filename |
These are the three important commands for File compression. | gzip filename, gunzip filename, gzcat 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 | gzip filename |
It uncompresses files compressed by gzip | gunzip filename |
gzcat filename | Lets you look at a gzipped file without actually having to gunzip it (same as gunzip -c). |
List 5 Important commands used for printing | 1pr filename 1pq 1prm jobnumber gensript dvips filename |
Command used to make a new directory | mkdir dirname |
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 |
Tells you where you currently are. | pwd |
What does W command helps us with to know about people? | 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. |
What is grep string filename(s) used for | 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, and even doing serious corpus work. |
It 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. | ff |
who | 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. |
_________ _______________ 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. | finger 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. | last -1 username |
It lets you have a (typed) conversation with another user | talk username |
_________ _______________ lets you exchange one-line messages with another user | write username |
_________ 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. | elm |
whoami | 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. |
It shows the disk usage of the files and directories in filename (without argument the current directory is used). du -s gives only a total. | du filename |
It 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 phonebill if you're making a non-local phonecall for dialling in. | last yourusername |
show what your disk quota is, how much you're actually using, and in case you've exceeded your quota how much time you have left to sort them out (by deleting or gzipping some, or moving them to your own computer). | quota -v |
finger | 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 |
It ends the processes with the ID you gave. This works only for your own processes. | kill PID |
lets you change your password, which you should do regularly (at least once a year). | passwd |
ps -u yourusername | 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. |
It allows you to read news. It will first let you read the news local to turing, and then the remote news. | nn |
If you want to read only the local or remote news, you can use ___ or ___, respectively. To learn more about nn type nn, then ______________________, then __________, then hit the space bar to step through the manual. | 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. |
rlogin hostname | rlogin hostname lets you connect to a remote host |
telnet hostname | telnet hostname also lets you connect to a remote host. Use rlogin whenever possible. |
It 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. | lynx |
It 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. | ftp hostname |
Looks up the word in an electronic version of Webster's dictionary and returns the definition(s) | webster word |
Shows the current date and time | date |
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. | cal |
To 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. | lprm jobnumber |
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 |
print. Use the -P option to specify the the printer name if you want to use a printer other than your default printer | lpr filename |
It 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. | genscript |
To 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 | lpq |