Command history simplifies router input operations

This article mainly introduces the command history record in Linux, which can simplify the work of the Administrator on the command line. This article provides a detailed introduction to this problem.

Similar functions are available in the command line environment of Linux. These command history records simplify the work of the administrator under the command line. In fact, this feature is also available in the IOS operating system of the router. It is more powerful than the command line environment in Windows or Linux.

I. default settings of the system

The command history function is very helpful for using long or complex commands for multiple times. By default, the command history function is enabled. That is to say, the system will automatically record the last ten commands in the History buffer zone. Of course, these default settings can be changed by the network administrator as needed. For example, you can reset the size of the command history cache to save more commands, or disable the command cache function. It is necessary to master these default configurations before you understand the subsequent operations and maintenance commands.

Ii. simplest application: Use the Tab key to complete the command line

In vro management, some commands are relatively long. For example, most of Cisco's IOS software uses English words and seldom uses acronyms. At this time, if you want to complete a word during maintenance, this not only requires a relatively high level of English for the network administrator, but also the efficiency is not high. To enable the advanced editing feature of a vro, enter the command terminal editing. A single character cannot be wrong. This command is relatively simple. However, it is difficult for an eight-level English Postmaster to complete the input.

Is there a simple way? The answer is yes. The command history function provides a command completion function. That is to say, the Administrator does not need to complete all input when entering commands. Instead, you only need to enter the first few characters and then enter the Tab key. The system will automatically complete the subsequent content. Simply put, when you enter a command, the administrator can enter a unique string that represents the command, and then press the Tab key to complete subsequent command lines for you on the user interface. Note that there is a uniqueness requirement here.

As shown in, if you want to enter terminal in the command line, you do not need to enter all. You only need to enter the first few characters, such as te, and then press the Tab key. The system will automatically complete the subsequent characters to simplify the system administrator input.

In addition, it must be noted that the command complementing function is different from the command complementing function in Linux. In Linux, there is no requirement for uniqueness. That is to say, if the entered characters are not unique, enter the Tab key and the system will list all commands starting with this input character. In the IOS command line, if the entered characters are not unique, pressing the Tab key will not respond. This may be improved in later IOS versions. I first learned the Linux operating system and then switched to network maintenance. At the beginning, I was not used to it. I believe that the network administrator will have a similar experience.