Variable expansion is the term used for the ability to access and manipulate values of variables and parameters. Basic expansion is done by preceding the variable or parameter name with the $ character. This provides access to the value.
$ UULIB=/usr/lib/uucp $ print $UULIB /usr/lib/uucp
Other types of expansion can be used to return portions or the length of variables, use default or alternate values, check for mandatory setting, and more.
For the sake of convenience, the term variable will refer to both variables and parameters in the following sections that discuss variable expansion.
This is expanded to the value of variable. The braces are used to protect or delimit the variable name from any ...