in reply to Re^3: trying to implement file tail with regular expression
in thread trying to implement file tail with regular expression

Thanks for your reply. I am new to Perl language so please be patient with me. for the first problem you mentioned, I dont understand what I should do here. GotToBTru suggested to put while (<DIAG>) first and put inside this loop the rest of the statements. maybe i misunderstand what he suggested. please help me to understand. for problem 2 i put the last as you suggested. for the third issue I completely removed the LOGFILE because I dont need it. the purpose of this script is to check a diagnostic file (.dia) which is continuously updated and once it match a statement "higher than 5 seconds" to shutdown a service and start it again. and then continue to work. below is the updated code please take a look and let me know what should i do as I am desperate :( :( :( 


#!C:\Perl64\bin\perl.exe

use File::Tail;

my $routerip;
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 "ROUTERIP") {
               $routerip = $val;
           }
           if ($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 $clock = 0;
while (<DIAG>) { 
    while (1) {
        while ($line = <DIAG>) {
            if ($line =~ /is higher than 5 seconds/) {
                if ($clock == 0) {
                    $clock = 60;
                    my $commandStr2 = "sc \\\\$hostName1 stop AudioSrv
+ >$app_root_dir\\logs\\StopServiceOutput1.txt" ;
                    system($commandStr2);
                    my $commandStr4 = "sc \\\\$hostName2 stop AudioSrv
+ >$app_root_dir\\logs\\StopServiceOutput2.txt" ;
                    system($commandStr4);
                    sleep(5);
                    my $commandStr3 = "sc \\\\$hostName1 start AudioSr
+v >$app_root_dir\\logs\\StartServiceOutput1.txt";
                    system($commandStr3);
                    my $commandStr5 = "sc \\\\$hostName2 start AudioSr
+v >$app_root_dir\\logs\\StartServiceOutput2.txt";
                    system($commandStr5);
                }
                $clock --;
            }
            last;        
        }
    }
}

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Re^5: trying to implement file tail with regular expression
by poj (Abbot) on Feb 16, 2016 at 12:01 UTC

    Try this. Note I have used a module to read the ini file.

    #!perl
use strict;
use File::Tail;
use Config::Tiny;

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

my $app_root_dir = shift;

=head1 content of param.ini 
DIAGFILE  = diagfile
HOSTNAME1 = hostname1
HOSTNAME2 = hostname2
=cut
my $Config = Config::Tiny->read( "$app_root_dir/config/param.ini" )
      or die "$!";

my $ref = tie *DIAG,"File::Tail",(
    name        => $Config->{'_'}{'DIAGFILE'},
    interval    => 1,  # wait at start
    maxinterval => 10, # change to suit
    adjustafter => 10  # change to suit
);

my $restart;
while (my $line = <DIAG>) { 
  if ($line =~ /is higher than 5 seconds/) {
    # restart only if more than 60 seconds since last restart
    if (time() - $restart > 60) {
      run_command('stop',1);
      run_command('stop',2);
      run_command('start',1);
      run_command('start',2);
      $restart = time();
    }
  }
}

# execute start/stop
sub run_command {
  my ($action,$n) = @_;
  my $host = $Config->{_}{'HOSTNAME'.$n};
  my $cmd = join ' ','sc',"\\\\$host",$action,'AudioSrv',
  ">$app_root_dir\\logs\\${action}ServiceOutput${n}.txt";

  #system($cmd); 
  print "$cmd\n"; # replace with system after testing
}

    [download]
    poj
[reply]
[d/l]

      again thanks for your support. I tried your code but I faced the same issue. when its reaching while (my $line = <DIAG>) its stop. I am using Eclipse for step by step troubleshooting. I dont understand why this is happening. without using the file tail class it works fine and I was able to read from the file!!!!!! do you have any other idea please?

[reply]

        Perhaps try it without tie.

        #my $ref = tie *DIAG,"File::Tail",(
#    name        => $Config->{'_'}{'DIAGFILE'},
#    interval    => 1,  # wait at start
#    maxinterval => 10, # change to suit
#    adjustafter => 10  # change to suit
#);

my $fh = File::Tail->new(
  name        => $Config->{'_'}{'DIAGFILE'},
  interval    => 1,  # wait at start
  maxinterval => 10, # change to suit
  adjustafter => 10  # change to suit
);

my $restart;
#while (my $line = <DIAG>) { 
while (my $line = $fh->read) { 
  print $line;
  if ($line =~ /is higher than 5 seconds/) {
.
.

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        This was the log generator I use to test the script

        #!perl
use strict;

my $n = 3; my $s = 10;
print "Log generator running .. $n events every $s secs .. \n";
open OUT,'>','c:/temp/diag.log' or die "$!";
select OUT; $|=1;
while (1){
  print STDOUT scalar localtime."\n";
  for (1..$n){
    print scalar localtime,"-  abc is higher than 5 seconds xyz\n";
  }
  print scalar localtime."- some other log message $_\n" for 0...rand(
+10);
  sleep($s);
}

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        poj
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