char *search( pat, text )
     char *pat, *text;

     { char *p;

       if( *pat == EOS ) return( text );
       for( p=pat; *text != EOS; text++ ) {
          if( *text != *p ) { text -= (p-pat);  p = pat; }
          else if( *(++p) == EOS ) return( text - (p-pat) + 1 );
          }
       return( NULL );
     }