In Linux, files are arranged in a hierarchical structure of directories or folders. A directory is simply a container for your files. Directories can further have subdirectories. The Linux file structure spans in a manner similar to branches of a tree and is hence commonly referred to as a tree structure. It begins with a root directory, which is referenced using /, or forward slash, on the terminal. The root directory contains a number of system directories and files that govern your Linux system.
In this guide, developers and sysadmins will learn how to interact with files and directories in Linux using the command line.
How to Display File Content in Linux
First, you need to know the files in the directory you are currently in. To list the files in your current directory, use the ls command:
To display the contents of a given file to your terminal window, you can use the cat command, followed by the file name. For example:
$ cat filename1
Copying File Content in Linux Directories
There are some instances where you may need to copy a file to another directory (or even the same one). For this, use the cp command. The syntax is:
$ cp [source] [destination]
The source indicates the filename of the file to be copied. In case you are working from a directory different from the file, you can instead indicate its file path. The destination is the directory to which you would like to save the copied file:
$ cp filename1 /home/joel/
The above command creates a copy of filename1 and then saves it to the directory /home/joel/ with the same file name.
You also have the option to save the file with a different name. Simply add the new filename at the end of the file path, as shown below:
$ cp filename2 /home/joel/filename3
See the example below on how you can make a copy of a file to the same directory:
$ cp filenameX filenameY
Moving and Deleting Files in Linux Directories
Moving a file refers to shifting it to a different directory. This is different from copying a file, since the original file is removed from its initial directory. To move a file, use the mv command, followed by the filename name and its destination directory:
$ mv filenameX /tmp
It’s interesting to note that the mv command can be used to rename a file. The example below renames file3 to file4:
$ mv file3 file4
To delete a file, use the rm command, followed by the filename. You may need administrative privileges. If prompted to do so, prefix the rm command with sudo.
$ rm filename2
Directory Management in Linux
As mentioned earlier, files are stored in directories. In most operating systems, a directory is commonly referred to as a folder. To create a directory, type the mkdir command followed by the directory name and run the command:
$ mkdir folder1
You may want to know your present working directory. Simply run the pwd command in you terminal to do so:
To list the contents in your current directory, run the ls command.
To change your current directory, use the cd command followed by the directory you would like to change to.
$ cd /etc
In case you want to delete a directory, use the rmdir command followed by the directory name.
$ rmdir /tmp/folder1
If the directory you are deleting has sub-directories, your system will flag an error when you run rmdir. To recursively delete folders, add the -r option.
You may also want to move a folder into another folder. Use the syntax below to achieve this:
$ mv folder1/ folder2/
If you want to copy all the file contents in a folder, you will still use the cp command, though, you will need to add the -R option:
$ cp -R folder1/ folder2/
Summary of File Management in Linux
Directories are used for organizing files in your Linux system. When creating your own directories and subdirectories, it is only fair that your arrangement is logical while doing so (since directories are meant to help you organize files and other directories). Keep this in mind when tackling the task of managing your files in Linux.