k9core/src/head.c

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

int
head(FILE *file, int lines)
{
  if(file == NULL)
    {
      printf("error opening file\n");
      return 1;
    }
  int a;
  int c = 0;

  while((a = fgetc(file)) != EOF)
    {
      if(a == '\n')
	++c;

      putchar(a);
      if(c == lines)
        return lines;
    }
  return lines;

}

int
main(int argc, char *argv[])
{
  int lines = 10;
  switch(argc)
    {
    case 1:
      head(stdin,lines);
      break;
    case 2:
      head(fopen(argv[1],"r"),lines);
      break;
    case 3:
      lines = abs(atoi(argv[1]));
      head(fopen(argv[2],"r"),lines);
      break;
    default:
      lines = atoi(argv[2]);
      head(fopen(argv[3],"r"),lines);
      break;
    }
  return 0;
}