Unix in a Nutshell, 4th Edition

Name

set

Synopsis

    set [-r] variable = value
    set [-r] variable[n] = value
    set [-f | -l] variable=(list)
    set [-r] variable
    set [-r]

Set variable to value or, if multiple values are specified, set the variable to the list of words in the value list. If an index n is specified, set the n th word in the variable to value. (The variable must already contain at least that number of words.) If only variable is specified, set the variable to null. With no arguments, display the names and values of all set variables. See also the section “Predefined Shell Variables,” earlier in this chapter. Only one of -f or -l can be given.

Options

-f

When setting a variable to a list, remove duplicate words from the list, keeping only the first occurrence of a duplicate.

-l

When setting a variable to a list, remove duplicate words from the list, keeping only the last occurrence of a duplicate.

-r

List only read-only variables, or set specified variable to read-only.

Examples

% set list=(yes no maybe)     
                     Assign a wordlist
    % set list[3]=maybe           
                     Assign an item in existing wordlist
    % set quote="Make my day"    
                     Assign a variable
    % set x=5 y=10 history=100    
                     Assign several variables
    % set blankAssign a null value to blank