Introduction to Unix commands. Following is a very brief introduction to some useful Unix commands, including examples of how to use each command. For more extensive information about any of these commands, use the man command as described below. Sources for more information appear at the end of this document.
On this page: cal. This command will print a calendar for a specified month and/or year. To show this month's calendar, enter: cal To show a twelve- month calendar for 2. To show a calendar for just the month of June 1. This command outputs the contents of a text file.
You can use it to read brief files or to concatenate files together. To append file. 1 onto the end of file. To view the contents of a file named myfile, enter: cat myfile. Because cat displays text without pausing, its output may quickly scroll off your screen. Use the less command (described below) or an editor for reading longer text files. For more, see In Unix, how do I combine several text files into a single file? This command changes your current directory location.
By default, your Unix login session begins in your home directory. To switch to a subdirectory (of the current directory) named myfiles, enter: cd myfiles. To switch to a directory named /home/dvader/empire. To move to the root directory, enter: cd /To return to your home directory, enter: cdchmod. This command changes the permission information associated with a file. Saajna Falak Song Mp3 Download on this page.
Every file (including directories, which Unix treats as files) on a Unix system is stored with records indicating who has permission to read, write, or execute the file, abbreviated as r, w, and x. These permissions are broken down for three categories of user: first, the owner of the file; second, a group with which both the user and the file may be associated; and third, all other users. These categories are abbreviated as u for owner (or user), g for group, and o for other. To allow yourself to execute a file that you own named myfile, enter: chmod u+x myfile To allow anyone who has access to the directory in which myfile is stored to read or execute myfile, enter: chmod o+rx myfile You can view the permission settings of a file using the ls command, described below. How To Install Wine On Fedora 16 Desktop. Note: Be careful with the chmod command.
If you tamper with the directory permissions of your home directory, for example, you could lock yourself out or allow others unrestricted access to your account and its contents. For more, see In Unix, how do I change the permissions for a file? This command copies a file, preserving the original and creating an identical copy. If you already have a file with the new name, cp will overwrite and destroy the duplicate. For this reason, it's safest to always add - i after the cp command, to force the system to ask for your approval before it destroys any files.
The general syntax for cp is: cp - i oldfile newfile To copy a file named meeting. Note: You must have permission to read a file in order to copy it. For each mounted file system, df reports the file system device, the number of blocks used, the number of blocks available, and the directory where the file system is mounted. To find out how much disk space is used on each file system, enter the following command: df If the df command is not configured to show blocks in kilobytes by default, you can issue the following command: df - kdu This command reports disk usage (i. The du command descends all subdirectories from the directory in which you enter the command, reporting the size of their contents, and finally reporting a total size for all the files it finds. To learn which is the case, use the man command, described below.
How to Configure X11 in Linux. In the Linux world, X11 (XFree86 or Xorg) provides the tools needed to use graphical applications. Without them, Linux would still be. Bindkey: tcsh
On most systems, du - k will give sizes in kilobytes. This command is most commonly used to find all of the files that have a certain name.
A command-line user interface (CLI), also known as a console user interface, and character user interface (CUI), is a means of interacting with a computer program.
It can be replaced by the full pathname of another directory to search. For instance, to search for files named myfile. On some systems, omitting the final / (slash) after the directory name can cause find to fail to return any results. For a list of suspended jobs, enter: jobs Each job will be listed with a number; to resume a job, enter % (percent sign) followed by the number of the job. To restart job number two, for example, enter: %2 This command is only available in the csh, bash, tcsh, and ksh shells.
Use this command as a last resort to destroy any jobs or programs that you suspended and are unable to restart. Use the jobs command to see a list of suspended jobs. To kill suspended job number three, for example, enter: kill %3 Now check the jobs command again. If the job has not been cancelled, harsher measures may be necessary.
Enter: kill - 9 %3less and more Both less and more display the contents of a file one screen at a time, waiting for you to press the Spacebar between screens. This lets you read text without it scrolling quickly off your screen. The less utility is generally more flexible and powerful than more, but more is available on all Unix systems while less may not be.
For example, to read the output of the ls command one screen at a time, enter: ls - la . To exit either less or more, press q. To exit less after viewing the file, press q. Note: Do not use less or more with executables (binary files), such as output files produced by compilers. Doing so will display garbage and may lock up your terminal. The lpr command is used on BSD systems, and the lp command is used in System.
V. Both commands may be used on the UITS systems. To see a brief, multi- column list of the files in the current directory, enter: ls To also see . If you are unsure how to use a command or want to find out all its options, you might want to try using man to view the manual page. To see one line summaries of each reference page that contains the keyword you specify, enter: man - k keyword Replace keyword in the above example with the keyword which you want to reference. Also see In Unix, what is the man command, and how do I use it to read manual pages?
This command will make a new subdirectory. You can use mv not only to change the directory location of a file, but also to rename files. Unlike the cp command, mv will not preserve the original file. Note: As with the cp command, you should always use - i to make sure you do not overwrite an existing file. Entered without arguments, it lists basic information about interactive processes you own. However, it also has many options for determining what processes to display, as well as the amount of information about each.
Like lp and lpr, the options available differ between BSD and System V implementations. For example, to view detailed information about all running processes, in a BSD system, you would use ps with the following arguments: ps - alxww To display similar information in System V, use the arguments: ps - elf For more information about ps refer to the psman page on your system. Also see In Unix, what do the output fields of the ps command mean?
This command reports the current directory path. Enter the command by itself: pwd. For more, see In Unix, how do I determine my current working directory? This command will remove (destroy) a file. You should enter this command with the - i option, so that you'll be asked to confirm each file deletion. To remove a file named junk, enter: rm - i junk. Note: Using rm will remove a file permanently, so be sure you really want to delete a file before you use rm.
To remove a non- empty subdirectory, rm accepts the - r option. On most systems this will prompt you to confirm the removal of each file. This behavior can be prevented by adding the - f option. To remove an entire subdirectory named oldstuff and all of its contents, enter: rm - rf oldstuff. Note: Using this command will cause rm to descend into each subdirectory within the specified subdirectory and remove all files without prompting you. Use this command with caution, as it is very easy to accidently delete important files.
As a precaution, use the ls command to list the files within the subdirectory you wish to remove. To browse through a subdirectory named oldstuff, enter: ls - R oldstuff . To remove a subdirectory named oldstuff, enter: rmdir oldstuff Note: The directory you specify for removal must be empty. To clean it out, switch to the directory and use the ls and rm commands to inspect and delete files. To edit a file named myfile in the current directory, enter: vi myfile The vi editor works fairly differently from other text editors. If you have not used it before, you should probably look at a tutorial, such as How do I use the vi text editor?
The very least you need to know to start using vi is that in order to enter text, you need to switch the program from command mode to insert mode by pressing i. To navigate around the document with the cursor keys, you must switch back to command mode by pressing Esc. To execute any of the following commands, you must switch from command mode to ex mode by pressing : (the colon key): Enter w to save; wq to save and quit; q! If you use w, you also get a list of what they are doing.
If you use who, you also get the IP numbers or computer names of the terminals they are using. At Indiana University, for personal or departmental Linux or Unix systems support, see At IU, how do I get support for Linux or Unix? This document was developed with support from National Science Foundation (NSF) grants 1.