Some useful Linux Commands...

01. ls – The most frequently used command in Linux to list directories

02. pwd – Print working directory command in Linux

03. cd – Linux command to navigate through directories

04. mkdir – Command used to create directories in Linux

05. mv – Move or rename files in Linux

06. cp – Similar usage as mv but for copying files in Linux

07. rm – Delete files or directories

07. touch – Create blank/empty files

07. ln – Create symbolic links (shortcuts) to other files

08. cat – Display file contents on the terminal

09. clear – Clear the terminal display

10. echo – Print any text that follows the command

11. less – Linux command to display paged outputs in the terminal

12. man – Access manual pages for all Linux commands

13. uname – Linux command to get basic information about the OS

14. whoami – Get the active username

15. tar – Command to extract and compress files in Linux

16. grep – Search for a string within an output

17. head – Return the specified number of lines from the top

18. tail – Return the specified number of lines from the bottom

19. diff – Find the difference between two files

20. cmp – Allows you to check if two files are identical

21. comm – Combines the functionality of diff and cmp

22. sort – Linux command to sort the content of a file while outputting

23. export – Export environment variables in Linux

24. zip – Zip files in Linux

25. unzip – Unzip files in Linux

25. ssh – Secure Shell command in Linux

26. service – Linux command to start and stop services

27. ps – Display active processes

28. kill and killall – Kill active processes by process ID or name

29. df – Display disk filesystem information

30. mount – Mount file systems in Linux

31. chmod – Command to change file permissions

32. chown – Command for granting ownership of files or folders

33. ifconfig – Display network interfaces and IP addresses

34. traceroute – Trace all the network hops to reach the destination

35. wget – Direct download files from the internet

36. ufw – Firewall command

37. iptables – Base firewall for all other firewall utilities to interface with

38. apt, pacman, yum, rpm – Package managers depending on the distro

39. sudo – Command to escalate privileges in Linux

40. cal – View a command-line calendar

41. alias – Create custom shortcuts for your regularly used commands

42. dd – Majorly used for creating bootable USB sticks

43. whereis – Locate the binary, source, and manual pages for a command

44. whatis – Find what a command is used for

45. top – View active processes live with their system usage

46. useradd and usermod – Add new user or change existing users data

47. passwd – Create or update passwords for existing users

What is Cyber Risk?

There are three levels of knowledge and according to the scope of knowledge, there are differences in human behavior...

There are three levels of knowledge and according to the scope of knowledge, there are differences in human behavior...

First level: When a person enters the first level of knowledge after acquiring some basic knowledges, he/she becomes arrogant and thinks that he/she knows or has learned everything.

Second level: When a person is able to understand something as soon as he/she knows it, it can be called the second level of knowledge. At this stage he/she becomes humble, and his/her curiosity grows for acquiring more knowledge.

Third level: When the complete knowledge comes on all matters and he/she enters the third or higher level of knowledge by easily acquiring the skill of understanding everything well, he/she easily realize his/her mistakes. Even after knowing a lot, he/she thinks or realize that he/she knows nothing.

We have to try to reach the higher level for acquiring knowledge.

-Collected

MySQL JDBC Driver - Time Zone Issue

MySQL JDBC Driver - timezone issue or the server timezone value 'unknown' is unrecognized or represents more than one value, etc. occurred then following step would help to resolve: 

Just add the following line end of JDBC connection string,

?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC

Complete connection string below,

jdbc:mysql://hostname_or_ip:port/db_name?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC

MySQL InnoDB ib_logfile0, ib_logfile1 & ibdata1 file size issue

Following steps would solve the issue:

Step-1: MySQLDump all databases into a SQL text file (e.g. SQLDataBackup.sql)

Step-2: Drop all databases (except mysql, information_schema and performance_schema schemas)

Step-3: Shutdown MySQL

Step-4: Add the following lines to (/etc/my.cnf if linux) or (C:\xampp\mysql\data\my.ini if xampp in windows)

[mysqld]

innodb_file_per_table 

innodb_flush_method=O_DIRECT 

innodb_log_file_size=1G 

innodb_buffer_pool_size=4G 

innodb_data_file_path=ibdata1:10M:autoextend 

Note: Whatever you set for innodb_buffer_pool_size, make sure innodb_log_file_size is 25% of innodb_buffer_pool_size.

Step-5: Delete ibdata1, ib_logfile0 and ib_logfile1  

There should only be the mysql schema in data location.

Step-6: Restart MySQL

This will recreate ibdata1 at 10MB (do not configure the option) , ib_logfile0 and ib_logfile1 at 1G each

Step-7: Reload SQLDataBackup.sql into MySQL

ibdata1 will grow but only contain table metadata and intermittent MVCC data. Each InnoDB table will exist outside of ibdata1

Suppose you have an InnoDB table named mydb.mytable. If you go into path/mysql/data, you will see two files representing the table

mytable.frm (Storage Engine Header) 

mytable.ibd (Home of Table Data and Table Indexes for mydb.mytable) 

ibdata1 will never contain InnoDB data and Indexes anymore.

With the innodb_file_per_table option in (/etc/my.cnf if linux) or (C:\xampp\mysql\data\my.ini if xampp in windows), you can run OPTIMIZE TABLE mydb.mytable OR ALTER TABLE mydb.mytable ENGINE=InnoDB; and the file will actually shrink.

Excel Digit Conversion

English to Bangla Digit Conversion and vice-versa

Download the Excel File

Number to words both in English & Bangla (PHP Version)

https://github.com/tomamuns/InWords-PHP-