perl 检测自己是否运行

#### create myself pid file
my $pid = $$;
my $myname=$0;
print "myname: $myname\n";
my $pidFile = "/export/web/tmp/handle_report.pid";

#### check other myself,if exists then exit else write myself pid to pidfile
if ( -s "$pidFile") {
    open PIDF, $pidFile || die "Can't open file $pidFile $!\n";
    my $oldPid;
    while () {
        $oldPid=$1 if ($_ =~ /^(\d+)/);
    }
    close(PIDF);
    if($oldPid) {
        #my $is_exist = qx/ps x -o 'pid' |grep -w "$oldPid"/;
        #if($is_exist)
        if(-d /proc/$oldPid )
        {
        print "Warn: already exist other myself pid=$oldPid,exit or kill $oldPid,check pidfile $pidFile\n";
        exit;
        }
    }
}
#### other check method
my @psname = qx#ps x -o 'pid,cmd' | grep -w "$myname" | grep -Ev 'grep|/bin/sh'#;
if(@psname >1) {
    print "Warn: ps name $myname already exist other myself exit\n";
    exit;
}

my $insertPID=qx/echo $pid >$pidFile/;