Report writing for fundamental of computing (week 10)

Fundamental of Computing DO3

On 10th week I learned about fundamental commands in Linux, basic file operations, and an introduction to the Linux file system. I also learned more advanced commands, such as those for process management, system monitoring, and package management. The explanation of the "ls -al" command and examples for interpreting its output are also taught by our lecturer. Additionally, the content briefly touched on text editors like VI or VIM, Nano, and gedit. In the second section we  discussed the Linux file system, highlighting the directory tree, pathname, and different types of files in Linux, including regular files, directories, special files, sockets, pipes, and links. And to know more , some examples are shown to illustrate practical usage scenarios for these commands and concepts

Basic Command in Linux

The command given below are used in Linux;

·       ls: Lists the contents of a directory.

·       cd: Changes the current working directory.

·       pwd: Prints the current working directory.

·       mkdir: Creates a new directory.

·       rmdir: Removes a directory.

·       rm: Removes a file.

·       cp: Copies a file or directory.

·       mv: Moves or renames a file or directory.

·       touch: Creates a new empty file.

·       file: Checks the type of a file.

·       grep: Searches for a pattern in a file.

·       cat: Concatenates files and prints them to the standard output.

·       more: Displays a file one page at a time.

·       less: Displays a file one page at a time, but allows you to scroll back and forth.

·       diff: Compares two files and shows the differences.

·       man: Displays the manual page for a command.

Here are some more advanced Linux commands:

·       ps: Lists the currently running processes.

·       kill: Kills a process.

·       top: Displays a real-time view of the system's processes and resources.

·       sudo: Allows you to run commands as another user, typically the root user.

·       apt-get: Installs and removes software packages on Debian-based systems.

·       yum: Installs and removes software packages on Red Hat-based systems.

·       tar: Creates and extracts archive files.

·       gzip: Compresses files.

·       unzip: Decompresses files.

·       ssh: Connects to a remote computer securely.

·       scp: Copies files between two computers securely.

·       ftp: Transfers files between two computers using the File Transfer Protocol.

Ls –R : shows all the files not only in directories but also subdirectories

        

Ls –al : This command lists the contents of the current directory in a long format, which includes additional information about the files and directories, such as their permissions, owner, group, size, and last modified date.

The columns in the output of the ls -al command are as follows:

File type and access permissions: The file type (ordinary file, directory, symbolic link, etc.) and access permissions are shown in this column. Three characters are used to represent the different access rights: these reflect the permissions for the owner, group, and world, respectively.

# of HardLinks to the File: This column shows the number of hard links to the file. A hard link is a direct pointer to the file's data on the disk.

Owner and the creator of the file: This column shows the name of the user who owns the file and the name of the group to which the file belongs.

Group of the owner: This column shows the name of the group to which the file belongs.

File size in Bytes: This column shows the size of the file in bytes.

Date and Time: This column shows the date and time when the file was last modified.

Directory or File name: This column shows the name of the file or directory.

Here is an example of how to interpret the output of the ls -al command:

• first example

total 12

drwxr-xr-x 2 user user 4096 Nov 2 08:42 .

drwxr-xr-x: This indicates that it is a directory (d), and the permissions for the owner, group, and others are set to read (r), write (w), and execute (x).

"2": The number of hard links to the directory.

user user: The owner and group of the directory.

4096: The size of the directory in bytes.

Nov 2 08:42: The last modification time of the directory.

• second example

drwxr-xr-x 4 user user 4096 Nov 2 08:42 ..

drwxr-xr-x: This indicates that it is a directory (d), and the permissions for the owner, group, and others are set to read (r), write (w), and execute (x).

"4": The number of hard links to the directory. In the case of .., this typically represents the number of subdirectories and the parent directory itself.

"user user": The owner and group of the directory.

"4096": The size of the directory in bytes. For directories, this value represents the amount of disk space used by the directory's metadata, not the size of its contents.

"Nov 2 08:42": The last modification time of the directory.

"..": The name of the directory. In a directory listing, ".." refers to the parent directory

• third example

-rw-r--r-- 1 user user 1024 Nov 2 08:42 example.txt

"-rw-r--r--": This indicates that it is a regular file (-), and the permissions for the owner, group, and others are set to read (r) and write (w) for the owner, and read (r) for the group and others.

"1": The number of hard links to the file.

"user user": The owner and group of the file.

"1024": The size of the file in bytes.

"Nov 2 08:42": The last modification time of the file.

"example.txt": The name of the file.

The ls -al command is a very useful tool for getting information about the files and directories in your Linux system. You can use it to see what files are in a directory, to check the permissions on a file, to see when a file was last modified, and more.

 

Ls –a :command to view hidden files

How to create folder

To create directory inside other directory use mkdir /other directory name/new Directory

 

rmdir: removes an empty directory.

grep (global regular expression print)  :Used to search text in files and print that matches the given pattern.

 

History : Shows all the commands used in the past for the current terminal sessions.

clear : Clears all the clutter on the terminal. Refreshes the terminal display, removing previous content.

Text Editor

VI or VIM is a text editor designed for the terminal, suitable for creating various file types. You can initiate it using the <vi> or <vim> commands.

Nano is a different text editor that is now accessible for investigation. The integrated gedit programme is a graphical user interface (GUI) text editor that you may use if you'd rather. Just use the <gedit> command to launch it. The command <gedit file_name> can be used to open a particular file in gedit.

Fundamental of  Computing EO1

Linux file system is a builtin layer used to handle the data management of the storage.

The Linux file system has a directory tree that manages the file name, file size, creation date and much more information about a file.

 

Source: 

Linux Directory Structure - Tech Fry

 

Pathname: text string made up of one or more names separated by forward slashes(/) used to find something in the hierarchical file system tree.

Files are organized within a single tree hierarchical file system structure made up of files containing data and directories.

File Types in Linux

In Linux system, everything is a file and if it is not a file it is a process and are of seven types.

1. Regular Files: These are the most common files in Linux, storing data like text or program code, and are meant for user-readable content.

2. Directories: Used to organize and store files and other directories, helping maintain a structured file system.

3. Character Device Files (special files): include character and block devices, representing hardware components like keyboards (character) and hard drives (block). They allow interaction with hardware.

4. Block device files (special files): represent storage hardware like hard drives and SSDs, handling data in fixed-size blocks.

5. Local Domain Sockets: Serve as communication endpoints for inter-process communication (IPC), enabling data exchange between processes on the same system or over a network.

6. Named Pipes (FIFOs): Facilitate communication between processes through a first-in, first-out mechanism, typically on the same system.

7. Link Files: Act as shortcuts to other files or directories, providing an alternative or simplified access path.

There are two types:

1. Hard Link: creates a mirror copy of the original file.

2.  Symbolic or Soft Link: contains a reference to another file or directory by its pathname