Functions for Transforming Text

Functions allow you to do text processing in the makefile to compute the files to operate on or the commands to use in recipes. You use a function in a function call, where you give the name of the function and some text (the arguments) for the function to operate on. The result of the function’s processing is substituted into the makefile at the point of the call, just as a variable might be substituted.

• Syntax of Functions		How to write a function call.
• Text Functions		General-purpose text manipulation functions.
• File Name Functions		Functions for manipulating file names.
• Conditional Functions		Functions that implement conditions.
• Foreach Function		Repeat some text with controlled variation.
• File Function		Write text to a file.
• Call Function		Expand a user-defined function.
• Value Function		Return the un-expanded value of a variable.
• Eval Function		Evaluate the arguments as makefile syntax.
• Origin Function		Find where a variable got its value.
• Flavor Function		Find out the flavor of a variable.
• Make Control Functions		Functions that control how make runs.
• Shell Function		Substitute the output of a shell command.
• Guile Function		Use GNU Guile embedded scripting language.