#include<stdio.h>
#include<string.h>
void mystrcat(char *, char *);
main( )
{
  char source[ ] = "world" ;
  char target[15] = "hello";
  mystrcat ( target, source ) ;
  printf ( "source string = %s\n", source ) ;
  printf ( "target string = %s\n", target ) ;
  system("pause");
}
void mystrcat ( char *t, char *s )
{
  while ( *t != '\0' )
     t++;
  
  while(*s != '\0')
  {
     *t = *s;
     t++;
     s++;               
  }
  *t = '\0';
}