The table below lists the symbols that the ANSI C standard requires.

This macro	is
__DATE__	The date at which the file is compiled; for example, "Jul 14, 1995".
__FILE__	The name of the file being compiled; for example "prog.c".
__func__	The name of the function currently being compiled. This predefined symbol is only available under the emerging ANSI/ISO C9X standard.
__LINE__	The line number of the line being compiled. This is the number before including any header files.
__TIME__	The time at which the file is compiled in 24-hour format; for example, "13:01:45".
__STDC__	Defined as 1 if compiling C source code. This macro lets you know that Metrowerks C implements the ANSI C standard. This macro is undefined when compiling C++ source code.

Listing 7.1 shows a small program that uses the ANSI predefined symbols.

#include <stdio.h>

void main(void)
{
  printf("Hello World!\n");
  
  printf("%s, %s\n", __DATE__, __TIME__);
  printf("%s, line: %d\n",  __FILE__, __LINE__);
}

The program prints something like the following:

Hello World!
Oct 31 1995, 18:23:50
main.ANSI.c, line: 10