extern char* strcpy ( char *pStr1, char *pStr2 );

char*  strcpy ( char *pStr1, char *pStr2 )
{
  int i;
  char *p = pStr1;

  /* Copy all characters */
  for ( i = 0; *pStr2 != 0; i++ )
    *pStr1++ = *pStr2++;

  /* Add '/0' at the end of string */
  *pStr1 = 0;

  return p;
} /* end of strcpy() function */

#include "string.h"

char    buf[255]="first";
char    buf2[255]="second";
void main ( void )
{
    while(1)
    {
        strcpy(buf,buf2);
    } // end of while
} // end of main