Built-in functions test certain conditions at either read-time or run-time. They are used in expressions with the conditional constructs. The following built-in functions are available:
旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿑unction Name 쿏escription � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%defined(macro) 쿝eturns 1 if macro is defined;� � �0 otherwise � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%dir(dirspec) 쿝eturns 1 if dirspec specifies� � 쿪 valid and existing � � 쿭irectory; 0 otherwise � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%exist(filespec) 쿝eturns 1 if filespec exists � � �(as a file or directory); 0 � � 쿽therwise � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%exists(filespec) 쿔s a synonym for %exist( � � �filespec) � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%file(filespec) 쿝eturns 1 if filespec � � 퀂pecifies a valid and existing� � 쿯ile; 0 otherwise � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%member(word, word_list) 쿝eturns 1 if word is contained� � �-- as a separate, blank � � 쿭elimited word -- in word_list� � �; 0 otherwise. The search is � � 쿬ase-insensitive. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%status() 쿝eturns the return code of the� � 쿹ast user command invoked. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �%writable(filespec) 쿝eturns 1 if filespec � � 퀂pecifies a valid and existing� � 쿭irectory or file that is not � � 퀁ead-only; 0 otherwise. � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
Example:
Built-in functions can be used just like other values in expressions:
!if %defined(macro1) && ("$(macro2)" == "ON") &&
%exists($(target))
This directive is evaluated to non-zero if macro1 is defined, macro2 has the definition "ON", and the file name defined in the macro target exists as a file or directory.