/* @(#) fitspass.c 1.4 98/07/09 13:40:43 */
/* Copyright (c) 1993 Association of Universities for Research 
 * in Astronomy. All rights reserved. Produced under National   
 * Aeronautics and Space Administration Contract No. NAS5-26555.
 */
/* fitspass.c   Read FITS header from infile and pass it to outfile,
 *              Adds blank lines to make header a multiple of 36 lines.
 *              This may exit with error status if some problem is found.
 *
 * Parameters:
 * FILE *infile         input file
 * int  passthru        non-zero -> copy header to outfile
 * FILE *outfile        output file
 *
 * Programmer: R. White     Date: 16 April 1992
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

extern int myread(FILE *infile, char *line, int n);

extern void fitspass(FILE *infile, int passthru, FILE *outfile)
{
char line[80];
int i, j;

    /*
     * Note that the SIMPLE line has already been stripped off and written
     * to outfile for FITS files, so we start at i=1
     */
    for (i = 1; ; i++) {
        if (myread(infile, line, 80) != 80) {
            fprintf(stderr,"FITS header has no END statement\n");
            exit(-1);
        }

        if (passthru) {
            if (fwrite(line,1,80,outfile) != 80) {
                perror("stdout");
                fprintf(stderr, "fitspass: error writing output file\n");
                exit(-1);
            }
        }

        if (strncmp(line,"END ",4) == 0) break;
    }
    /*
     * write blank lines to make a multiple of 36 lines in header
     * number of lines written so far is i+1
     */
    if (passthru) {
        for (j=0; j<80; j++) line[j]=' ';
        for (i = 35 - (i % 36); i>0; i--) {
            if (fwrite(line,1,80,outfile) != 80) {
                perror("stdout");
                fprintf(stderr, "fitspass: error writing output file\n");
                exit(-1);
            }
        }
    }
}