Declare variables and give them attributes.
SYNTAX declare [-afFrxi] [-p] [name[=value]] OPTIONS -a Each name is an array variable. -f Use function names only. -F Inhibit the display of function definitions; only the function name and attributes are printed. (implies -f) -i The variable is to be treated as an integer; arithmetic evaluation is performed when the variable is assigned a value. -p Display the attributes and values of each name. When '-p' is used, additional options are ignored. -r Make names readonly. These names cannot then be assigned values by subsequent assignment statements or unset. -x Mark each name for export to subsequent commands via the environment.
If no names are given, then 'declare' will display the values of variables instead.
Using + instead of - turns off the attribute instead.
When used in a function,
declare makes each name local, as with the
typeset command is supplied for compatibility with the Korn shell; however, it has been deprecated in favor of the
The return status is zero unless an invalid option is encountered, an attempt is made to define a function using '-f foo=bar', an attempt is made to assign a value to a readonly variable, an attempt is made to assign a value to an array variable without using the compound assignment syntax, one of the names is not a valid shell variable name, an attempt is made to turn off readonly status for a readonly variable, an attempt is made to turn off array status for an array variable, or an attempt is made to display a non-existent function with '-f'.
"My mother never saw the irony in calling me a son-of-a-bitch" ~ Jack Nicholson
Related linux commands:
alias - Create an alias.
env - Display, set, or remove environment variables.
echo - Display message on screen.
export - Set an environment variable.
hostname - Print or set system name.
local - Create variables.
printenv - Print environment variables.
readonly - Mark variables/functions as readonly.
shift - Shift positional parameters.
Equivalent Windows command: SET - Display, set, or remove Windows environment variables.