perl串口通信实例

使用串口通信，在备机端使用如下脚本检测来自主机的心跳信号，一旦未接受次数超过指定记数，备机认为主机DOWN机，自动设置为主机的网络参数，顶替主机提供服务。

# ! 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=255.255.255.0

set address name="local" gateway=192.168.6.65 gwmetric=0

set dns name="local" source=static addr=192.168.6.112 register=PRIMARY

add dns name="local" addr=192.168.6.201 index=2

set wins name="local" source=static addr=none

popd

# 接口 IP 配置结束

' ; # 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 ;