Create delete copy and move files and directories

In this lesson, we explore essential Linux commands to create, delete, copy, and move files and directories. Understanding these commands is crucial for effective file management in Linux. Before using these commands, ensure you are familiar with these fundamental concepts:

• What is a file system tree?
• What is an absolute path?
• What is a relative path?

Listing Files and Directories

The ls command lists the files and directories in your current (or working) directory. The term ls is short for "list." Here are several common usages:

Basic Listing

Running the simple ls command in a typical home directory might display:

$ ls
Pictures    Desktop
Documents   Videos
Downloads   Music

Files and directories starting with a dot (such as .ssh) are hidden by default. To view hidden files, include the -a option:

$ ls -a
.              ..
.ssh           .bash_logout   .bash_profile  .bashrc
Pictures       Desktop        Downloads       Documents   Music

Listing Files in a Specific Location

To list files from another directory, provide the path to the ls command:

$ ls /log

Long Listing Format

For extended details like permissions, ownership, and modification times, use the -l option:

$ ls -l /var/log/
total 4064
drwxr-xr-x. 2 root  root       4096 Oct 18 22:52 anaconda
drwx------. 2 root  root          23 Oct 18 22:53 audit
-rw-------. 1 root  root      19524 Nov  1 17:56 boot.log
-rw-rw----. 1 root  utmp          0 Nov  1 14:08 btmp
-rw-------. 1 root  utmp          0 Oct 18 22:38 btmp-20211101
drwxr-x---. 2 chrony chrony   6 Jun 24 09:21 chrony
...

Combining Options for Detailed and Inclusive Listings

The -a and -l options can be combined, and their order is not important:

$ ls -a -l
total 76
drwx------ 16 aaron aaron 4096 Nov  1 17:57 .
drwxr-xr-x  7 root  root    70 Oct 26 16:54 ..
-rw-------  1 aaron aaron 5085 Nov  1 17:56 .bash_history
-rw-r--r--  1 aaron aaron  141 Jul 27 09:21 .bash_logout
-rw-r--r--  1 aaron aaron  376 Jul 27 09:21 .bash_profile
-rw-r--r--  1 aaron aaron  141 Jul 27 09:21 .bashrc
drwxr-xr-x  2 aaron aaron    6 Oct 19 00:11 Desktop
drwxr-xr-x  3 aaron aaron   25 Oct 23 18:15 Documents
drwxr-xr-x  2 aaron aaron    6 Oct 19 00:11 Downloads
drwxr-xr-x  2 aaron aaron    6 Oct 19 00:11 Music
drwxr-xr-x  2 aaron aaron    2 Oct  6 19:37 Pictures
-rw-rw-r--  1 aaron aaron   36 Oct 28 20:06 testfile

To display file sizes in a human-friendly format (bytes, kilobytes, megabytes, etc.), combine the -h option:

$ ls -ahl
total 76K
drwx------   16 aaron  aaron  4.0K Nov  1 17:57 .
drwxr-xr-x    7 root   root    70 Oct 26 16:54 ..
-rw-------    1 aaron  aaron  5.0K Nov  1 17:56 .bash_history
-rw-r--r--    1 aaron  aaron    18 Jul 27 09:21 .bash_logout
-rw-r--r--    1 aaron  aaron   141 Jul 27 09:21 .bash_profile
-rw-r--r--    1 aaron  aaron   376 Jul 27 09:21 .bashrc
drwxr-xr-x    2 aaron  aaron     6 Oct 19 00:11 Desktop
drwxr-xr-x    3 aaron  aaron    25 Oct 23 18:15 Documents
drwxr-xr-x    2 aaron  aaron     6 Oct 19 00:11 Downloads
drwxr-xr-x    2 aaron  aaron     6 Oct 19 00:11 Music
drwxr-xr-x    2 aaron  aaron     6 Oct 19 00:11 Pictures
-rw-rw-r--    1 aaron  aaron    36 Oct 28 20:06 testfile

Understanding the File System Tree

Linux organizes all files and directories into a hierarchical structure known as the file system tree. Think of it like an inverted tree, where the root directory (/) sits at the top, and all subdirectories branch out from there.

Paths Explained

Absolute Path

An absolute path starts from the root directory. For example:

/home/aaron/Documents/Invoice.pdf

This path begins at the root (/), moves through the home directory, then aaron, followed by Documents, and finally accesses the file Invoice.pdf.

Relative Path

A relative path describes a location relative to the current working directory. To see your current working directory, use the pwd command:

$ pwd
/root

If you're logged in as user Aaron with the starting directory /home/aaron, the path Documents/Invoice.pdf would reference /home/aaron/Documents/Invoice.pdf. Likewise, Invoice.pdf without any directory designation refers to a file in the current directory, while ../Invoice.pdf navigates one level up.

Consider this structure: the root directory (/) branches into several subdirectories and further levels until it eventually leads to files like "Invoice.pdf".

Creating Files and Directories

Creating files and directories in Linux is simple with the following commands:

Creating Files

The touch command creates a new, empty file. For example, to create a file named Receipt.pdf in the current directory:

$ touch Receipt.pdf

To create a file in another location, specify the file path. Both absolute and relative paths work:

$ touch /home/jane/Receipt.pdf
$ touch ../jane/Receipt.pdf

Creating Directories

Use the mkdir command (short for "make directory") to create new directories. For instance:

$ mkdir receipts

Copying Files and Directories

The cp command copies files and directories with ease.

Copy a File

To copy a file, provide its source path and destination path:

$ cp Receipt.pdf receipts/

It is advisable to end directory paths with a slash (/) to indicate that the destination is a directory. You can also copy a file and rename it simultaneously:

$ cp Receipt.pdf receipts/Receipt_copy.pdf

Copy a Directory Recursively

To duplicate an entire directory and its contents, use the -r (recursive) flag:

$ cp -r Receipts/ BackupOfReceipts/

Moving and Renaming Files and Directories

The mv command is versatile—it moves files or folders and also renames them.

Moving a File

To move a file to a different location:

$ mv Receipt.pdf receipts/

Renaming a File or Directory

To rename Receipt.pdf to old_receipt.pdf:

$ mv Receipt.pdf old_receipt.pdf

When moving directories, mv automatically processes all contained files and subdirectories without needing a recursive flag.

Deleting Files and Directories

Deleting files and directories is straightforward with the rm command.

Deleting Files

To remove a file:

$ rm Invoice.pdf

Deleting Directories Recursively

To delete a directory and all its contents, use the -r option:

$ rm -r Invoices/

Visual aids, like command-line interfaces and directory structure diagrams, can help illustrate how paths reference files such as "Invoice.pdf". However, the commands function independently of any visual representations.

Summary

In this lesson, you learned how to:

• List files and directories utilizing ls and its various options (-a, -l, -h).
• Understand the differences between absolute and relative paths.
• Create files with touch and directories with mkdir.
• Copy files and directories using cp, including the recursive copy option for entire directories.
• Move and rename files or directories with mv.
• Delete files using rm and remove directories recursively with rm -r.

Happy learning and efficient file management in Linux!