declare command in Linux with Examples

The declare is a builtin command of the bash shell. It is used to declare shell variables and functions, set their attributes and display their values.

Syntax:

declare [-a] [-f] [-g] [-F] [-x] [-p] [name[=value]] [name[=value]] …

Example: In this example we will declare a variable using declare command.

The output of the above typed commands is as follow:

Options:

• -p This is used to displays the options and attributes of each variable name if it is used with name arguments.

  Example:

  

• -f : Each name is treated as the name of function, not variable. So you can say this option restrict action or display to function names and definitions.
• -F : When showing information regarding a function, it show only the function’s name and attributes. So the contents of the function will not be displayed.
• -g : It causes all operations on variables to take effect in global scope.

Note: For more details, you can use –help option with “declare” command as follows: