2.5 Include Files

There are five major classes of include files: system, VICAR main, VICAR system, VICAR subroutine, and local.
Include only those files needed. Some includes require that other files be included first. Extra includes in your program don't gain you anything, but slow down your compiles. They also make system maintenance difficult, since the source code must occasionally be searched to see what programs use an include, and all programs that use an include must be recompiled when it changes (even if it's not really used).
System include files are provided by the operating system. Many are OS-specific, but there are a few that are standard across platforms. Make sure the ones you need are available in both operating systems, or isolate them in machine-dependent code. System include files should be enclosed in angle brackets and have the “.h” extension. Some known portable includes are:

#include <varargs.h>
#include <math.h>
#include <ctype.h>
#include <stdio.h>

One known non-portable file is <unistd.h>. If you need symbolic constants for the lseek() arguments(which are often contained in unistd.h), use the definitions provided in xvmaininc.h.
The VICAR main include file, which all VICAR programs should start with, must be in lower case, with double quotes. The name of the main include is “vicmain_c”, with no directory specifiers and no “.h” extension.
Any modules other than the main program module that need VICAR definitions should include xvmaininc.h, in lower case, with double quotes and the “.h” extension xvmaininc.h is automatically included with vicmain_c.

#include “vicmain_c” 
— or —
#include “xvmaininc.h”

VICAR system includes are provided as part of the RTL. Their names should be in lower case, with quotes and the “.h” extension. The valid ones are listed below. Only a few of these should ever be used in application code, notably zvproto.h, ftnbridge.h, errdefs.h, and applic.h. The rest should only be needed in very unusual circumstances. They should generally be in the order listed below.
Include only those needed. Extraneous include files will only slow down your compile and make system maintenance harder. TAE includes are handled as specified in the TAE documentation. They should be in double quotes, with the ”.inc” or “.inp” extensions as appropriate. The first four listed below are TAE includes:

#include “taeconf.inp” 
#include “symtab.inc” 
#include “parblk.inc” 
#include “pgminc.inc” 
#include “zvproto.h” 
#include “defines.h” 
#include “declares.h” 
#include “externs.h” 
#include “applic.h” 
#include ”errdefs.h” 
#include “ftnbridge.h” 
#include “xviodefs.h”

VICAR subroutine include files (class 2 and 3 SUBLIB, VRDI, etc.) should be in double quotes, with no path names, and should include the “.h” extension, like VICAR system includes. For these includes, the directories containing the includes must be available to the compiler. This is normally handled transparently, but some libraries will require a LIB_* macro in the imakefile to access the includes.

#include “vmachdep.h” 
#include “gll_ssi_edr.h” 
#include “xderrors.h”

Local includes, which are delivered as part of the COM file and are used only by that application, should be in double quotes, with no path names. Include the “.h” extension, just as for VICAR system and subroutine includes. Local includes must be listed in the INCLUDE_LIST macro in the imakefile so they can be cleaned up properly.

#include “my_inc.h”