Shulou(Shulou.com)06/01 Report--

This article mainly introduces the relevant knowledge of "how to use the declare command of Linux". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "how to use the declare command of Linux" can help you solve the problem.

The Linux common command declare command is used to declare and display existing shell variables. Displays all shell variables when no variable name argument is provided. The declare command displays all shell variables and their values without any parameter options. The function of declare is the same as that of the typeset command.

Syntax declare [+ / -] [rxi] [variable name = set value] or declare-f parameter description:

+ /-"-" can be used to specify the properties of a variable, and "+" is to cancel the properties set by the variable.

-f displays only functions.

R sets the variable to read-only.

The variable specified by x becomes an environment variable and can be used by programs other than shell.

I [set value] can be a numeric value, a string or an expression.

The example first uses the declare command to define the shell variable "test" and sets its value to "lnmp.ailinux.net". Enter the following command:

After declare test='lnmp.ailinux.net' # defines and initializes the command above the shell variable, use the echo command to output the value of the shell variable, enter the following command:

Echo $test # outputs the value of the shell variable. After the instruction above is executed, the output is as follows:

This is the end of lnmp.ailinux.net 's introduction to "how to use Linux's declare commands". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.