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Department of Civil and Environmental Engineering
Frank Batten College of Engineering and Technology
Old Dominion University
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Creating/Renaming/Deleting Files and Directories


  

You can make a new directory with the "mkdir" (make directory) command, and you can remove an empty directory with the "rmdir" (remove directory) command. If there is any files under a directory you want to delete, you need to use -R (recursive) flag to delete the directory and files under it.

Let's assume that following examples are done in the home directory of user "wclinton."

You type It does
$ mkdir timber create a directory timber in current directory
$ mkdir ~/grisly create a directory grisly in home directory
$ mkdir /home/wclinton/grisly the same as above example
$ rmdir starr delete a directory starr in current directory
$ rmdir -R ~/whitewater delete a directory whitewater AND all files/subdirectories under it
$ mkdir -R
   /home/wclinton/whitewater
the same as above example

Time to time, you'd like to know where in the file tree a directory resides before using any of "mkdir" or "rmdir" command. In such case, use "pwd" (print working directory) command to display the absolute pathname of your current working directory.

Directories under Unix can be renamed and moved around with a single command. For example, whole "/data/life_saver" directory (and whatever under it) can be moved to home directory by :

$ mv ~/data/life_saver ~

Files can be moved around in a similar way. To rename a file under Unix, you use the "mv" (move) command. For example, to change the name of file "foo" to "boo" in current directory, you can type :

$ mv foo boo

You can also copy files with the "cp" (copy) command. Here is an explanation by examples:

$ cp batman robin

makes a duplicate of the file "batman" and gives it the name "robin" in the current directory. Note that the filenames can include pathnames as well. Let's say that you're currently in "/home/wclinton/project" directory.

$ cp /home/wclinton/project/batman ./robin

Above "cp" command makes a copy of the file "batman" found in the "/home/wclinton/project" directory and places it in the current working directory (= /home/wclinton) into a file called "robin. "

If you don't specify the filename for "cp" command, the same filename (=source filename) will be used to create a duplicate.

$ cp catwoman /home/wclinton/project

Above "cp" command makes a copy of the file "catwoman" found in current directory to a file "/home/wclinton/project/catwoman. " The filename, "catwoman" will remain unchanged.

Same manner, following "cp" command makes a copy of the file "joker" found in "/home/wclinton/project" directory to the current directory. The filename, "joker" will remain unchanged.

$ cp /home/wclinton/project/joker .

You can also use a wildcard character, an asterisk that matches any number of characters in a filename, to copy all the files (but not the subdirectories) from a directory all at once.

$ cp /home/wclinton/project/* .

will copy all the files (but not the subdirectories if there is any) from "/home/wclinton/project" directory into the current directory at once. Hence, you can copy all the files and subdirectories (if there is any) from "/home/wclinton/project" directory to the current directory by using the "-R" (recursive) flag as follows:

$ cp -R /home/wclinton/project/* .

Same manner, to copy everything from the "/home/wclinton/secret" directory into the "shredder" directory under the home directory (assuming the "shredder" directory already exists):

$ cp -R ~/secret/* ~/shredder

Keep in mind that all wildcard characters can be used for "cp" and "mv" commands.

Another useful flag for "cp" command is the "-i" (interactive) flag which will prompt for confirmation if you are about to overwrite an existing file(s) that happens to be the same filename(s) you're copying from. A "y" answer means that the copy should proceed. Any other answer prevents "cp" from overwriting. It is a nice cautionary measure, however it can be a tiresome routine if used repeatedly.

You can delete a file with the "rm" (remove) command. Be careful if you type "rm *", because Unix doesn't ask you if you're sure you want to do that. Also, there is NO UNDELETE MECHANISM for the Unix file system. When a file is gone, it's gone! BE CAREFUL. ONLY DELETE WHAT YOU WANT TO DELETE.

If you're unsure about whether a wildcard will pick up only what you want, do "ls" with that wildcard first, to see what it matches, then run the "rm. "

You type It does
$ rm uh-oh.txt delete a file uh-oh.txt in current directory
$ rm ~/brainstorm/not_a_good.idea delete a file not_a_good.idea under directory brainstorm
$ rm /home/wclinton/brainstorm/not_a_good.idea the same as above example

Of course, similarly like in "cp" command, you can use "-i" (Interactive) flag with "rm" command to confirm before removing any files.

The bottomline is that you should know what you're doing when you're using "cp", "mv", "rm" and "rmdir" commands.

Make a good habit to visualize what will be the result before issuing any one of those commands.


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