Conditional Commands

The conditional commands can be used to control the behaviour of the command lines of rules. The syntax is exactly the same as the syntax for conditional directives, except that conditional commands are indented with a tab; they appear in the body of a rule along with other commands. Nesting is supported.

Here is an example of where a conditional command might be useful for checking out RCS files, when the RCS directory is not accessible by the Make program (when knowledge of RCS file organization is private to RCS itself):

%.c:
    if nexists($@)
        $(CO) -u $@
    endif