| layout | title | published |
|---|---|---|
default |
makerule |
true |
[%CFEngine_function_prototype(target, sources)%]
Description: Evaluates whether a target file needs to be built or
rebuilt from one or more sources files.
[This function can accept many types of data parameters.][Functions#collecting functions]
The function is provided to emulate the semantics of the Unix make program.
In a traditional Makefile, rules take the form
target: source1 source2 ..
(tab) commands
The top line evaluates to a predicate for executing a number of commands, which is true
if the target file does not exist, or if any of the sources dependencies
in the list has been changed since the target was last built.
The makerule function emulates the same semantics and sets a class if the target needs to be built or rebuit, i.e. if the top line of an equivalent makefile is true.
[%CFEngine_function_attributes(target, sources)%]
The sources argument may be either a scalar (indicating a single
source) or a list reference or a data container. If the sources
argument specifies a list, then the entire list of sources is used to
determine whether the target needs rebuilding.
Example:
classes:
"build_me" expression => makerule("/tmp/target", "/tmp/source.c");
"build_me_ab" expression => makerule("/tmp/target", '["/tmp/source.a","/tmp/source.b"]' );
commands:
build_me::
"/usr/bin/gcc -o /tmp/target /tmp/source.c";
History: The [collecting function][Functions#collecting functions] behavior was added in 3.9.
See also: [About collecting functions][Functions#collecting functions].