Make/Values
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6.4 How Variables Get Their Values
Variables can get values in several different ways:
- You can specify an overriding value when you run
make
. See Overriding Variables. - You can specify a value in the makefile, either with an assignment (see Setting Variables) or with a verbatim definition (see Defining Multi-Line Variables).
- Variables in the environment become
make
variables. See Variables from the Environment. - Several automatic variables are given new values for each rule. Each of these has a single conventional use. See Automatic Variables.
- Several variables have constant initial values. See Variables Used by Implicit Rules.