builtin help declare

[shoebill]

declare: declare [-aAfFgilnrtux] [-p] [name[=value] ...]
    Set variable values and attributes.

    Declare variables and give them attributes.  If no NAMEs are given,
    display the attributes and values of all variables.

    Options:
      -f        restrict action or display to function names and definitions
      -F        restrict display to function names only (plus line number and
        source file when debugging)
      -g        create global variables when used in a shell function; otherwise
        ignored
      -p        display the attributes and value of each NAME

    Options which set attributes:
      -a        to make NAMEs indexed arrays (if supported)
      -A        to make NAMEs associative arrays (if supported)
      -i        to make NAMEs have the `integer' attribute
      -l        to convert NAMEs to lower case on assignment
      -n        make NAME a reference to the variable named by its value
      -r        to make NAMEs readonly
      -t        to make NAMEs have the `trace' attribute
      -u        to convert NAMEs to upper case on assignment
      -x        to make NAMEs export

    Using `+' instead of `-' turns off the given attribute.

    Variables with the integer attribute have arithmetic evaluation (see
    the `let' command) performed when the variable is assigned a value.

    When used in a function, `declare' makes NAMEs local, as with the `local'
    command.  The `-g' option suppresses this behavior.

    Exit Status:
    Returns success unless an invalid option is supplied or a variable
    assignment error occurs.