# ! perl -w   use strict; use Win32 :: SerialPort; my  $port  =  ' COM2 ' ; # serail port name registried in OS  my  $count  =  0 ; # count number of heartbeat-receiving failture  my  $max_count  =  5 ; # max fail count to be tolerated  my  $interface  =  '  # ---------------------------------- # 接口 IP 配置     # ---------------------------------- pushd interface ip# "local" 的接口 IP 配置set address name="local" source=static addr=192.168.6.185 mask=255.255.255.0set address name="local" gateway=192.168.6.65 gwmetric=0set dns name="local" source=static addr=192.168.6.112 register=PRIMARYadd dns name="local" addr=192.168.6.201 index=2set wins name="local" source=static addr=nonepopd# 接口 IP 配置結束 ' ; # net inetrface config information   sub errlog {   # log the failtrue occuring time       open ERR ,  ' >>err.log ' ;   my  @time  =  localtime ();   my  $time  =  sprintf ( " %d " ,  $time [ 5 ] +  1900 )              .  ' - '              .  sprintf ( " %d " ,  $time [ 4 ] +  1 )             .  ' - '              .  " $time[3] "              .  '  '              .  sprintf ( " %.2d " ,  $time [ 2 ])             .  ' : '              .  sprintf ( " %.2d " ,  $time [ 1 ])             .  ' : '              .  sprintf ( " %.2d " ,  $time [ 0 ]);   print ERR $time . " /n " ;   close ERR;} sub ipchange {   # change ip addrress       open TMP ,  ' >tmp ' ;   print TMP $interface ;   close TMP;     eval {     system  ' netsh -f tmp ' ;     unlink  ' tmp ' ;  };     if ($@) { return  0 ;}   return  1 ;} my  $ob  = Win32 :: SerialPort -> new( $port ) or die  " CANNOT OPEN $port " ; # open serial port   eval {   # set serial port properties       $ob -> baudrate( 9600 );   $ob -> parity( ' none ' );   $ob -> databits( 8 );   $ob -> stopbits( 1 );   $ob -> handshake( ' none ' );};   if ($@) { die  ' SET FAILED ' ;} $ob -> write_settings or die  " CANNOT WRITE $port DRIVER " ; # write to port driver to make it active   while ( 1 ) {   # loop receiving heartbeat from remote machine  # change ip address after designated count of failture       my ( $length ,  $result ) =  $ob -> read ( 10 );     if ( $result ) {      $count  =  0 ;  } elsif ( $count  ==  $max_count ) {    errlog();     if (not ipchange()) { print  ' IP CHANGE FAILED ' ; }     last ;  }   else {      $count ++ ;  }     sleep ( 1 );} undef  $ob ;