The second example of use seems to fit your situation:

use File::Tail;
my $ref=tie *DIAG,"File::Tail",(name=>$name);
while (<DIAG>) {
  # your while (1) loop processing goes here
}
[download]

You open LOGFILE each time thru the outermost while, but close it only if the if statement is true. I would try to make this consistent; perhaps you don't need to close it, now that you have File::Tail to read it.

I believe you will not need the sleep statement anymore. File::Tail keeps track of how often it finds data, and adjusts how often it reads accordingly.

Thank you very much for your help. I did what you said but the issue is once I reach to while (<DIAG>) it hang for some reason. please help!!

 

use File::Tail;

my $diagfile;
my $Checkoutput;
my $hostName1;
my $hostName2;

sub init {
    my ($dir) = @_;
    my $line;
    my $var;
    my $val;
    open (LREP2, "$dir/config/param.ini");
    while ($line = <LREP2>) {
           chop $line;
           ($var,$val) = split(/=/, $line);
           
           if ($var eq "DIAGFILE") {
               $diagfile = $val;
           }
           if ($var eq "CHECKFILE") {
               $Checkoutput = $val;
           }
           if ($var eq "HOSTNAME1") {
               $hostName1 = $val;
           }
           if ($var eq "HOSTNAME2") {
               $hostName2 = $val;
           }
    }
    close LREP2;
}

#MAIN

die "Usage: $0 <app_root_dir>" unless @ARGV == 1;

my $app_root_dir = shift;
&init($app_root_dir);
my $line;
open (DIAG, "$diagfile");
my $ref=tie *DIAG,"File::Tail",(name=> $diagfile);
my $clock = 0;
while (<DIAG>){
    while (1) {
        open LOGFILE, ">>$app_root_dir/logs/detailedlog.log";
        while ($line = <DIAG>) {

            if ($line =~ /is higher than 5 seconds/) {
                if ($clock == 0) {
                    $clock = 60;
                    my $commandStr2 = "sc \\\\$hostName1 stop AudioSrv
+ >$app_root_dir\\logs\\StopServiceOutput1.txt" ;
                    print LOGFILE "about to execute=$commandStr2\n";
                    system($commandStr2);
                    print LOGFILE "just executed=$commandStr2\n";
                    my $commandStr4 = "sc \\\\$hostName2 stop AudioSrv
+ >$app_root_dir\\logs\\StopServiceOutput2.txt" ;
                    print LOGFILE "about to execute=$commandStr4\n";
                    system($commandStr4);
                    print LOGFILE "just executed=$commandStr4\n";
                    sleep(5);
                    my $commandStr3 = "sc \\\\$hostName1 start AudioSr
+v >$app_root_dir\\logs\\StartServiceOutput1.txt";
                    print LOGFILE "about to execute=$commandStr3\n";
                    system($commandStr3);
                    print LOGFILE "just executed=$commandStr3\n";
                    my $commandStr5 = "sc \\\\$hostName2 start AudioSr
+v >$app_root_dir\\logs\\StartServiceOutput2.txt";
                    print LOGFILE "about to execute=$commandStr5\n";
                    system($commandStr5);
                    print LOGFILE "just executed=$commandStr5\n";
                }
                $clock --;
                sleep(1);
            }    
            close LOGFILE;        
        }
        sleep(65);
    }
}
[download]

Hello mkhayat, and welcome to the Monastery!

the issue is once I reach to while (<DIAG>) it hang for some reason.

The nested loops in the MAIN code have the following structure:

while (<DIAG>){
    while (1) {
        open LOGFILE, ">>$app_root_dir/logs/detailedlog.log";
        while ($line = <DIAG>) {

            if ($line =~ /is higher than 5 seconds/) {
                if ($clock == 0) {
                    $clock = 60;
                    # call "print LOGFILE" then "system(...)", 4 times
                }
                $clock --;
                sleep(1);
            }    
            close LOGFILE;        
        }
        sleep(65);
    }
}
[download]

There are at least 3 problems here:

1. There are two while (<DIAG>) loops, one nested inside the other.
2. There is no last statement inside the while (1) loop, so that loop will never terminate.
3. As GotToBTru observed: Within the inner while ($line = <DIAG>) loop, you close the filehandle LOGFILE after the first iteration, so on all subsequent iterations the print LOGFILE ... statements have nowhere to write to.

In addition, you still have calls to sleep although GotToBTru advised that they are not needed when using the File::Tail module.

Hope that helps,

Athanasius <°(((>< contra mundum

Iustus alius egestas vitae, eros Piratica,