Multiple Language Support

As can be seen in the above example, EXTRACT lines are hidden from the FORTRAN compiler by adding the leading comment character `*'. In fact EXTRACT can use any of the following comment prefixes:-

    Prefix 		 Language



* 		 Fortran

/* 		 C (adds */ at end of line if required)

; 		 VAX MACRO

! 		 VAX DCL

# 		 UNIX script (see LEADING_SOURCE in next section)

% 		 TEX or LATEX

so that a file can freely mix modules containing source in all these languages. For simplicity this document will assume the language FORTRAN but could equally well refer to /*FILE lines or !IF lines.

If using EXTRACT with C, there are a couple of points to watch:-

• Leave a blank line after the /*FILE line (EXTRACT can get confused if the next line is e.g.

      #include <stdio.h>
  

  into thinking that the delimitor is #).

• Leave a space before a trailing */

Here is a sample C program:-

*FILE MEMBER=CDHSTC LIBRARY=SNOMAN LANGUAGE=C DATE=03:May:1996 */

#include <stdio.h>
#include <string.h>
#include <sys/utsname.h>
#define  MAXHOST 8

/*IF UNIX */
/*IF APOLLO */
/*$int cdhstc(hnf) */
/*ELSE */
int cdhstc_(hnf)
/*ENDIF */
char *hnf;
{
        int i = MAXHOST;
        struct utsname u;
        char q[MAXHOST+1];

        if (uname(&u) < 0) return(-1);
        sprintf(q,"%-*s",MAXHOST,u.nodename);
        strncpy(hnf,q,i);
        return(0);
}
/*ENDIF */
/*ENDFILE MEMBER=CDHSTC */