#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define LIM 81

int fgetline (FILE *, char *, int);
void rtrim (char *);

int
main (int argc, char *argv[])
{
  char line[LIM];
  FILE *fitsfile;

  // Usage
  if (argc < 2)
    {
      printf ("Usage: %s <fitsfile>\n", argv[0]);
      printf ("\n\nOutputs the header of <fitsfile>\n");
      return 1;
    }

  // Open file
  fitsfile = fopen (argv[1], "r");

  // Loop over file and output
  while (fgetline (fitsfile, line, LIM) > 0)
    {
      rtrim (line);
      printf ("%s\n", line);
      if (strcmp (line, "END") == 0)
	break;
    }

  // Close file
  fclose (fitsfile);

  return 0;
}

// Read a line of maximum length int lim from file FILE into string s
int
fgetline (FILE * file, char *s, int lim)
{
  int c, i = 0;

  while (--lim > 0 && (c = fgetc (file)) != EOF && c != '\n')
    s[i++] = c;
  if (c == '\n')
    s[i++] = c;
  s[i] = '\0';
  return i;
}

// Removes trailing blanks from string s
void
rtrim (char *s)
{
  int i, j = 0, n;

  n = strlen (s);
  for (i = n; i >= 0; i--)
    if (s[i] != '\0' && s[i] != '\n')
      if (!isspace (s[i]) && j == 0)
	j = i;
  s[++j] = '\0';

  return;
}