Linux Commands

[mayurwaghmode]

1. ls— To list directories.
2. pwd — To Print working directory.
3. cd — To navigate through directories.
4. mkdir — To create directories in Linux.
5. mv— Move or rename files in Linux.
6. cp — Similar usage as mv but for copying files in Linux.
7. rm — Delete files or directories.
8. touch — Create blank/empty files.
9. ln — Create symbolic links (shortcuts) to other files.
10. cat— Display file contents.
11. clear — Clear the terminal display.
12. echo — Print any text that follows the command.
13. less — Linux command displays paged outputs in the terminal.
14. man — Access manual pages for all Linux commands.
15. uname — Linux command to get basic information about the OS.
16. whoami — Get the active username.
17. tar — Command to extract and compress files in Linux.
18. grep — Search for a string within an output.
19. head — Return the specified number of lines from the top.
20. tail— Return the specified number of lines from the bottom.
21. diff — Find the difference between two files.
22. cmp — This allows you to check if two files are identical.
23. comm — Combines the functionality of diff and cmp.
24. sort — Linux command to sort the content of a file while outputting.
25. export — Export environment variables in Linux.
26. zip — Zip files in Linux.
27. unzip — Unzip files in Linux.
28. ssh — Secure Shell command in Linux.
29. service — Linux command to start and stop services.
30. ps — Display active processes.
31. kill and killall — Kill active processes by process ID or name.
32. df — Display disk filesystem information.
33. mount — Mount file systems in Linux.
34. chmod — Command to change file permissions.
35. chown — Command for granting ownership of files or folders.
36. ifconfig — Display network interfaces and IP addresses.
37. traceroute — Trace all the network hops to reach the destination.
38. wget — Direct download files from the internet.
39. ufw— Firewall command.
40. iptables— Base firewall for all other firewall utilities.
41. apt, pacman, yum, rpm — Package managers depending on the distribution.
42. sudo — Command to escalate privileges in Linux.
43. cal — View a command-line calendar.
44. alias— Create custom shortcuts for your regularly used commands.
45. dd — Majorly used for creating bootable USB sticks.
46. whereis — Locate the binary, source, and manual pages for a command.
47. find — To search file.
48. passwd — Create or update passwords for existing users.
49. top — View active processes live with their system usage.
50. useradd and usermod— Add new users or change existing user's data.
51. passwd— Create or update passwords for existing users.
52. | (pipe) — To combine more than one command.
53. vi — To edit a file using vi editor in the terminal.
54. whatis — Find what a command is used for.

[mayurwaghmode]

grep -i staticpod /var/lib/kubelet/config.yaml

[mayurwaghmode]

ps -ef | grep /usr/bin/kubelet

[mayurwaghmode]

sudo find / -name  kube-controller-man* |grep bin
sudo grep -r kube-controller-man /etc/

[mayurwaghmode]

find – search for files in a directory hierarchy
Usage: find [OPTION] [path] [pattern]
eg.

find file1.txt
find ­-name file1.txt

[mayurwaghmode]

grep­ print lines matching a pattern
Usage: grep [OPTION] PATTERN [FILE]...

grep -­i apple sample.txt   

[mayurwaghmode]

du -sh command will show the total disk usage of a file or directory in a human-readable format. For example, if you run du -sh /home/user/Documents, it will display the total size of the "Documents" directory in a human-readable format.

[mayurwaghmode]

How to find the particular directory or file despite not knowing the actual path

find / -name httpd.conf
find / -type d -name http

[mayurwaghmode]

to find the error message in a particular file or directory

grep error logs.txt
grep error *

[mayurwaghmode]

to compare two different files we can use diff and sdiff commands diff httpd.conf httpd.conf_bkp sdiff httpd.conf httpd.conf_bkp (side by side diff)