Now, let’s assume that we want to move these files to a new directory (‘Temp’). We will do this using the Unix mv (move) command. Remember to use tab completion:
ubuntu@:~/Learning_unix$ mkdir Temp
ubuntu@:~/Learning_unix$ mv heaven.txt Temp/
ubuntu@:~/Learning_unix$ mv earth.txt Temp/
ubuntu@:~/Learning_unix$ ls
Temp
ubuntu@:~/Learning_unix$ ls Temp/
earth.txt heaven.txt
For the mv command, we always have to specify a source file (or directory) that we want to move, and then specify a target location. If we had wanted to we could have moved both files in one go by typing any of the following commands:
mv *.txt Temp/
mv *t Temp/
mv *ea* Temp/
The asterisk * acts as a wild-card character, essentially meaning ‘match anything’. The second example works because there are no other files or directories in the directory that end with the letters ‘t’ (if there was, then they would be moved too). Likewise, the third example works because only those two files contain the letters ‘ea’ in their names. Using wild-card characters can save you a lot of typing.
The ‘?’ character is also a wild-card but with a slightly different meaning. See if you can work out what it does.
In the earlier example, the destination for the mv command was a directory name (Temp). So we moved a file from its source location to a target location, but note that the target could have also been a (different) file name, rather than a directory. E.g. let’s make a new file and move it whilst renaming it at the same time:
ubuntu@:~/Learning_unix$ touch rags
ubuntu@:~/Learning_unix$ ls
rags Temp
ubuntu@:~/Learning_unix$ mv rags Temp/riches
ubuntu@:~/Learning_unix$ ls Temp/
earth.txt heaven.txt riches
In this example we create a new file (‘rags’) and move it to a new location and in the process change the name (to ‘riches’). So mv can rename a file as well as move it. The logical extension of this is using mv to rename a file without moving it (you have to use mv to do this as Unix does not have a separate ‘rename’ command):
ubuntu@:~/Learning_unix$ mv Temp/riches Temp/rags
It is important to understand that as long as you have specified a ‘source’ and a ‘target’ location when you are moving a file, then it doesn’t matter what your current directory is. You can move or copy things within the same directory or between different directories regardless of whether you are in any of those directories. Moving directories is just like moving files:
ubuntu@:~/Learning_unix$ mv Temp/riches Temp/rags
ubuntu@:~/Learning_unix$ mkdir Temp2
ubuntu@:~/Learning_unix$ mv Temp2 Temp
ubuntu@:~/Learning_unix$ ls Temp/
earth.txt heaven.txt rags Temp2
This step moves the Temp2 directory inside the Temp directory. Try creating a ‘Temp3’ directory inside ‘Learning_unix’ and then cd to /tmp. Can you move Temp3 inside Temp without changing directory?
You’ve seen how to remove a directory with the rmdir command, but rmdir won’t remove directories if they contain any files. So how can we remove the files we have created (inside Learning_Unix/Temp)? In order to do this, we will have to use the rm (remove) command.
Please read the next section VERY carefully. Misuse of the
rmcommand can lead to needless death & destruction
Potentially, rm is a very dangerous command; if you delete something with rm, you will not get it back! It is possible to delete everything in your home directory (all directories and subdirectories) with rm, that is why it is such a dangerous command.
Let me repeat that last part again. It is possible to delete EVERY file you have ever created with the rm command. Are you scared yet? You should be. Luckily there is a way of making rm a little bit safer. We can use it with the -i command-line option which will ask for confirmation before deleting anything (remember to use tab-completion):
ubuntu@:~/Learning_unix$ cd Temp
ubuntu@:~/Learning_unix/Temp$ ls
earth.txt heaven.txt rags Temp2
ubuntu@:~/Learning_unix/Temp$ rm -i earth.txt heaven.txt rags
rm: remove regular empty file 'earth.txt' y
rm: remove regular empty file 'heaven.txt' y
rm: remove regular empty file 'rags' y
ubuntu@:~/Learning_unix/Temp$ ls
Temp2
We could have simplified this step by using a wild-card (e.g. rm -i *.txt) or we could have made things more complex by removing each file with a separate rm command. Let’s finish cleaning up:
rmdir Temp2/Temp3
rmdir Temp2
cd ..
rmdir Temp
Copying files with the cp (copy) command is very similar to moving them. Remember to always specify a source and a target location. Let’s create a new file and make a copy of it:
ubuntu@:~/Learning_unix$ touch file1
ubuntu@:~/Learning_unix$ cp file1 file2
ubuntu@:~/Learning_unix$ ls
file1 file2
What if we wanted to copy files from a different directory to our current directory? Let’s put a file in our home directory (specified by ~ remember) and copy it to the current directory (Learning_unix):
ubuntu@:~/Learning_unix$ touch ~/file3
ubuntu@:~/Learning_unix$ ls ~
Desktop Downloads media Pictures Templates Videos
Documents Learning_unix Music Public tutorial_materials
ubuntu@:~/Learning_unix$ cp ~/file3 .
ubuntu@:~/Learning_unix$ ls
file1 file2 file3
This last step introduces another new concept. In Unix, the current directory can be represented by a . (dot) character. You will mostly use this only for copying files to the current directory that you are in. Compare the following:
ls
ls .
ls ./
In this case, using the dot is somewhat pointless because ls will already list the contents of the current directory by default. Also note how the trailing slash is optional. You can use rm to remove the temporary files.