- Users – this tool is used for user management. Usually it shows who are currently logged in into system. It is one of the simplest commands of Linux system. It is mostly used for finding out the current logged in user only when it is required for the system admin.
Example: users
- Groups – this tool is for mostly new user to any linux base system. It usually shows all the groups as output if no argument is given. This tool is used to know the existing groups have in system. Also we can find particular groups by providing user as argument. This is a handy tool for any system reporting.
example: group [option] argument - Wc – word count. This command is used for find the total number of character, words, lines etc. This command have a very good feature which is it does not count white space. If we do not put any option then the default result shows four parameters of a file. These four parameters are: longest line, words, bytes and file name.
example: wc [option] filename - Tr – tr means translate. It works as translating content of a file. This command also works as a transformation tool. It can be used for lower case to upper case, upper case to lower case. This command also supports basic find and replacement. Simply this command is a command line content transformer .
example: tr [option] argument - Tc – traffic control and manipulation. This tool is simply used for network traffic control. It can do four basic works over network operations. It can shape the traffic, schedule the traffic, filter the traffic and finally it can drop the traffic. But whole operation is based on network operations.
example: tc [option] argument - Awk – this is a common tool used for scripting. We usually use this for text transformation or text editing. It’s a command line tool which can be used along with other commands for a better performance. As this is a scripting tool we can find few combined features of different tools in this one tool.
example: awk [option] regex argument - Blkid – blkid means block ID. It is used to find storage partition ID as a listed manner. Usually we get a UUID from this list which is used to put into the permanent storage record. It is important to make consistent and permanent mounted block storage for a server system. One of the very useful command tools for system administrator.
example: blkid device name - sed – this is a very powerful command for editing any content of a file. Sed means stream editor which can edit files without opening a file. It can be used for find and replace, searching, editing and deleting. Mostly it is being used for find and replace and deleting characters or words from syntax. We can use it by capturing line by line which makes it a very useful tool on Linux system.
example: sed [option] regex filename - >> – this is a tool that is used to redirect the result to a file. Usually this tool is used for appending on an existing file or a newly created file. It is used for keeping the record in a desired manner. This tool is simply works as print but this prints the output to a file.
example: ls >> file.txt - | – this tool is called piping. It is one of the most commonly used sign on linux terminal. This tool basically provides arguments to a command by taking the output from another command on terminal. Before using this tool we need to know the commands basic working principle of the commands we are going to use for any particular output.
Example: tail –f /var/log/message | grep –i route
