#include  "calcmarks.h"    // local header file provides declarations

int readmarks(FILE *fp)
{
    char     line[BUFSIZ];
    int      nmarks = 0;

    double   thisproj;
    double   thisexam;

    ....
//  READ A LINE FROM THE FILE, CHECKING FOR END-OF-FILE OR AN ERROR
    while( fgets(line, sizeof line, fp) != NULL ) {

//  WE'RE ASSUMING THAT WE LINE PROVIDES TWO MARKS
        ....     // get 2 marks from this line

        projmarks[ nmarks ] = thisproj;   // update global array
        exammarks[ nmarks ] = thisexam;

        ++nmarks;

        if(verbose) {     // access global variable
            printf("read student %i\n", nmarks);
        }
    }
    return nmarks;
}