3.3. Saving Commands

There may come a time when you will want to save certain commands to be executed when everything else is done. For instance: you are making several different libraries at one time and you want to create the members in parallel. Problem is, ranlib is another one of those programs that can not be run more than once in the same directory at the same time (each one creates a file called __.SYMDEF into which it stuffs information for the linker to use. Two of them running at once will overwrite each other's file and the result will be garbage for both parties). You might want a way to save the ranlib commands til the end so they can be run one after the other, thus keeping them from trashing each other's file. PMake allows you to do this by inserting an ellipsis (“...”) as a command between commands to be run at once and those to be run later.

So for the ranlib case above, you might do this:

lib1.a          : $(LIB1OBJS)
    rm -f $(.TARGET)
    ar cr $(.TARGET) $(.ALLSRC)
    ...
    ranlib $(.TARGET)

lib2.a          : $(LIB2OBJS)
    rm -f $(.TARGET)
    ar cr $(.TARGET) $(.ALLSRC)
    ...
    ranlib $(.TARGET)

This would save both

ranlib $(.TARGET)

commands until the end, when they would run one after the other (using the correct value for the .TARGET variable, of course).

Commands saved in this manner are only executed if PMake manages to re-create everything without an error.