If we want to work in linux servers, The knowledge of file/folder manipulation is a must. In this article, I'm going to share my knowledge about the linux commands about file/folder manipulation. In linux/unix not only the files and directories are treated as files but also everything. For example, devices, processes are also files.

What refers file/folder manipulation

File/folder manipulation refers the following

Create/edit/delete file or folders
Copy/move and rename files

Some other file operations not manipulation things

Listing files or directories with permissions
View files
View/change directories

Let's list down the main commands in file/folder manipulation area

mkdir
touch
cp
mv
rm
rmdir

Let's talk about them with some short description and examples

mkdir

The full form of mkdir is making directories where 'mk' stands for making and 'dir' for directories. So, this command is used for creating directories if not exists. If exists, it will not create one.

mkdir src

This command will create the src folder in the current directory.

Now we want to create a hierarchy of directories like this

mkdir src/com/leeonscoding/www

This will not work. Because the parents aren't existed. In here we need one option -p. So, the parents will also be created.

mkdir -p src/com/leeonscoding/www

If you need the details how those folders created then use another option -v

mkdir -p -v src/com/leeonscoding/www

The output may looks like this

src
src/com
src/com/leeonscoding
src/com/leeonscoding/www

rmdir

Let's remove the folders. In rmdir, rm stands for remove and dir for directory. If we run this command rmdir src we will get an error. Because the folder isn't empty, there are sub folders in it. But we can remove an empty folder using rmdir.

rmdir src/com/leeonscoding/www

The folder 'www' will delete. Now what if we need to delete the src folder with sub folders at once. We need the option parent -p

rmdir -p -v src/com/leeonscoding

Here -v for details(hierarchy) of the removal. The output is

src/com/leeonscoding
src/com
src

But what if there are files inside folder or folders. The rmdir will not work then. As we need to remove files too then it is a part of file too. I'll talk about it later in this article.

touch

The simple way of creating files is the touch command. Although the purpose of touch is changing timestamp of a file. In other word, we can also update a file using this command.

mkdir src && cd src && touch file1.txt file2.txt file3.txt

Here I've created 3 files. Let's check the timestamps.

ls -l

A sample output

total 0
-rw-r--r--  1 sufian  staff  0 Aug 19 13:30 file1.txt
-rw-r--r--  1 sufian  staff  0 Aug 19 13:30 file2.txt
-rw-r--r--  1 sufian  staff  0 Aug 19 13:30 file3.txt

Now update the timestamp of file1.txt. For being sure, I've put some text in that file. Now, again execute the touch command.

touch file1.txt

Again run the ls -l command

A sample output

total 8
-rw-r--r--  1 sufian  staff  12 Aug 19 14:30 file1.txt
-rw-r--r--  1 sufian  staff   0 Aug 19 13:30 file2.txt
-rw-r--r--  1 sufian  staff   0 Aug 19 13:30 file3.txt

Notice that the timestamp for file1.txt is changed from 13:30 to 14:30. Also you may notice the content of the file is unchanged. So, the file timestamp is only updated.

rm

The rm command is used for removing files, directories that contains files, device nodes etc.

rm file2.txt file3.txt

2 files will be deleted. Now let's try to remove the src directory. Using rm src will not work. We have to add an option -r here which represents recursive.

rm -r src

Now the src with its all child files and folders will be removed.

There are so many options in rm but some are useful I think. One is -i. Using this option, before deleting a file it will ask for your confirmation. If you press y, this command will delete the file and if you press n this command will keep the file.

rm -i file1.txt

Another one can be -d. Instead rmdir we can remove an empty directory using this option.

mv

The mv stands for move. In linux this command is used for 2 purposes

Moving files/folders from one directory to another.
Rename files/folders.

Let's move some files first.

mv src/java/lang/*.java src/java/util

In this code example, every file which has the extension .java in the directory src/java/lang move to the folder src/java/util directory.

Now, Create the same file(with same content) again in src/java/lang and repeat the same thing. It is time for overwrite. If we need a prompt for overwriting like this

overwrite src/java/util/String.java? (y/n [n])

Then we need an option -i

mv -i src/java/lang/*.java src/java/util

If we don't overwrite at all then use option -n and if we need overwrite without any question then -f

If you want to know which files are affected like this output

src/java/lang/String.java -> src/java/util/String.java

Then use -v

Now let's rename a file

mv -v src/java/util/Object.java src/java/util/Object2.java

Here we're not moving any file. We keep the file where it is. But change the name. You can check it using this command

ls src/java/util

cp

The cp stands for copy. It is similar to mv but copy files or directories.

cp src/java/lang/*.java src/java/util

It has similar options like

-i for interactive mode for overwrite files.
-n for not overwriting.

Unlike mv in cp copying a directory which has nested folders and multiple files, need an option -r (recursive) like we use in rm.

cp -r src project1

In this code example, I've copied one directory to another directory.

When we copy one file to another, the ownership and timestamp also changed. To preserve the originals we should use the option -p. Also, don't forget to use -v for checking what are the changes.

Replace text content from one file to another using cat

cat test1.txt > test2.txt

Here cat command will print everything from the test1.txt and using the redirect operator(>) the output will redirect to test2.txt. Nothing in test2.txt will exist then.

Conclusion

Hope this article is understandable and you guys learn something from this if you are new. If you like this article don't forget to give me a thumb. Happy coding.

File/folder manipulation commands in unix/linux what I know