We can view the dynamic information of all processes through two tools, top and htop, which support interactive viewing of processes.

We can view snapshot information for the current processes through the ps command.

We can view the process through the pgrep command, and we can signal the process through the pkill command.

Through the logical volume management technology provided by Linux, we can flexibly manipulate the file systems in every volume.

With RAID technology, we can combine multiple disks in some way to improve performance or reliability.

Linux provides us with a lot of tools to manage disks. These tools allow us to view disk usage and partition the drive.

Data is the most critical thing in the system, and the disk is the necessary hardware device to persist the data.

Awk is a flexible pattern matching, text processing and line-oriented language, Linux provides us with an implementation version of it, gawk.

We can use the sed stream editor provided by linux to filter and convert text line by line.

We can use the grep tool provided by linux to find matching rows based on either the basic or extended regular expressions.

In addition to the last line mode and edit mode, vim also provides us with two other modes: view mode for copying, pasting, deleting selected content, and insert mode to add and delete text.

In addition to last line mode, vim also has edit mode, both of which complement each other.

Through the last line mode of vim, we can easily execute some commands, such as switching between files, saving files, moving the cursor, deleting and replacing text and so on.

The Vim text editor provides instructions that make it easy for us to operate, through which we can open files in a variety of ways.

The find command provides some useful options for finding files or directories based on creation time, modification time, owner, group, permissions, type, size, etc.

To make our files more secure, Linux provides a feature called file attribute. By configuring the attributes of the file, we can specify whether it is read-only or undeleted, or in other statuses.

Although the chmod command is powerful enough, it cannot assign permissions more finely, so Linux provides some flexible commands to specify permissions for a particular user or group. Starting from Linux kernel 2.6, we can allocate more granular permissions to users or groups.

We can switch between users through the su and sudo commands. Also, we can use these two commands to perform certain command operations with the privileges of other users.

Linux provides users with tools to communicate with each other. Some can send messages to a specified user; some can send a group of messages; some can even send content as an email to a user’s inbox list.

Linux provides some commands to view the user: login status, login record, login attempt log, user last login log and so on.