#include<stdio.h>

#define BUFLEN 512

void mycat1(char * filename);
void mycat2(char * filename);

char* fn="myfile.txt";

int main()
{

  FILE * fp;

  fp = fopen(fn,"w");
  fprintf(fp,"Hello this is the first line of my file\n");
  fprintf(fp,"Line 2\n");
  fputs("Line 3\n",fp);
  fprintf(fp,"Line 4\n");
  fclose(fp);

  printf("Printing the file with mycat1 ...\n");
  mycat1(fn);
  printf("Printing the file with mycat2 ...\n");
  mycat2(fn);
  printf("END\n");

  fp = fopen(fn,"w+");
  fprintf(fp,"ABC\n");
  fclose(fp);

  printf("Printing the file...\n");
  mycat1(fn);
  printf("\n");

  return 0;
}

void mycat1(char * filename)
{
  FILE * fp = fopen(filename,"r");
  char c=0;
  while ( (c=getc(fp)) !=EOF)
  {
    putchar(c);
  }
  fclose(fp);
  return;
}


void mycat2(char * filename)
{
  char buf[BUFLEN];
  FILE * fp = fopen(filename,"r");
  while(fgets(buf,BUFLEN,fp))
    fprintf(stdout,"%s",buf); /* Note this is identical to printf */
  fclose(fp);
  return;
}