shroh:

Typically for handling files like that, I do this:

while (<$FH>) {
   # Remove leading and trailing whitespace from line
   s/\s+$//;
   s/^\s+//;

   # skip blank lines
   next if /^$/;

   # do stuff
}
[download]

This way, extra whitespace on a server line won't be a problem, nor will a blank line.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

Hi Rob, This is the error when i am using your logic. Variable "$MYFILE" is not imported at outage_nodes_updated.pl line 63. Global symbol "$MYFILE" requires explicit package name at outage_nodes_updated.pl line 63. Execution of outage_nodes_updated.pl aborted due to compilation errors.

#!C:\Perl\bin\perl.exe
use Win32;
use IO::Handle;
use File::Find;
use strict;
use warnings;
use File::Copy qw(copy);
#use Path::Tiny qw/ path /;

######################################################################
+##############
#This script is created to put the servers in unplanned outage as part
+ of the tasks#
#that are received to stop the monitoring on the servers
#due to some maintenance activity on the servers.
#
#
#

require "E:/Temp/inyrohs/omwNodeDetails.pm";


#expect values 'on|off'

my ($SEC,$MIN,$HOUR, $DAY, $MON, $YEAR)= (localtime) [0..6];

my $year=$YEAR+1900;
my $month=$MON+1;
my $day=$DAY;
my $date="$year\_$month\_$day";


my $LOG="E:/Temp/inyrohs/maintenanceMode_$date.log";

my $serverlist="E:/Temp/INYROHS/serverlist.txt";

 

 open( MYFILE, "E:/Temp/INYROHS/serverlist.txt") or die "Can't open '$
+serverlist': $!";

my @outagenodes=<MYFILE>;

#chomp(@outagenodes);


#print "@outagenodes\n";

my $maintMode=$ARGV[0]; 

chomp($maintMode);

open (LOG,">> $LOG") or die "Can't open $LOG file: $!\n";

printf LOG ("\nTime is %02d:%02d:%02d.\nStarting the maintenance mode 
+process to turn $maintMode outages.\n\n", $HOUR, $MIN, $SEC);

#print "$date \n";

#print "starting the process \n";



#print "maintMode: $maintMode:\n";


while (<$MYFILE>){


s/\s+$//;
s/^\s+//;

next if /^$/;


if($maintMode =~ m/on/)

   {        


foreach my $NODES (@outagenodes)

       {
            

           my @parts=split /\./, $NODES;

           my $hostname=$parts[0];

           chomp($hostname);

           my $fqdn = getNodeAttributes($hostname,"PrimaryNodeName");

           print "$hostname\n";
            
            #printLog("Node: $NODES, processing...\n");

            #print "entered loop \n";

    

           my $cmd="ovownodeutil.cmd -outage_node -unplanned -disable_
+heartbeat -delete_msgs -node_name $fqdn -$maintMode ";

            print "$cmd\n";

            `$cmd`;

            print "done with command\n";
 
        }

   }

         elsif($maintMode=~ m/off/)

        
   {


foreach my $NODES (@outagenodes)

       {


           my @parts=split /\./, $NODES;

           my $hostname=$parts[0];

           chomp($hostname);

         my  $fqdn = getNodeAttributes($hostname,"PrimaryNodeName");

           print "$hostname\n";


           printLog("Node: $NODES, processing...\n");

           printLog("Bringing the server $NODES out of outage.\n");

           my $cmd="ovownodeutil.cmd -outage_node -unplanned -disable_
+heartbeat -delete_msgs -node_name $fqdn -$maintMode";

           my $cmdresopcmona="ovdeploy -cmd \"ovc -restart opcmona\" -
+host $fqdn";

           my $cmdresopcle="ovdeploy -cmd \"ovc -restart opcle\" -host
+ $fqdn"; 
      
           print "$cmd\n";

           `$cmd`; 

           print "$cmdresopcmona\n";
 
           `$cmdresopcmona`; 
            

           print "$cmdresopcle\n";

           `$cmdresopcle`;                        
             
       }                      
            
           

  } 

}

truncate <MYFILE>,1;


sub printLog
{
    my ($logLine) = @_;
    chomp($logLine);
    $logLine=$logLine . "\n";
    print "$logLine"; print LOG "$logLine";
}
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shroh:

As the anonymous monk says, $MYFILE and MYFILE are two different things. You're opening your file with:

open( MYFILE, "E:/Temp/INYROHS/serverlist.txt") or die "Can't open '$s
+erverlist': $!";
[download]

Using this method, you have to use MYFILE to read from the file, not $MYFILE. My code uses $FH because current practice in perl is to open files like this:

open my $MYFILE, '<', "E:/Temp/INYROHS/serverlist.txt" or die "Can't o
+pen '$serverlist': $!";
[download]

There are several advantages to this method: It's easier to pass file handles to subroutines when you use lexical variables. Files will automatically close for you when they go out of scope (i.e. you get to the closing '}' of the block containing the definition.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

Why do you think the bareword filehandle MYFILE is related to a variable $MYFILE?

Hi shroh. In addition to the above suggestions, see the response to your other question referencing Path::Tiny::lines and its chomp => 1 attribute. This will remove the newline character from the lines as they are pushed onto the array of lines. Then you can just do next if $line =~ /^$/;

FAQ: How do I change, delete, or insert a line in a file, or append to the beginning of a file?

perl -ni.bak -e "print $_ if /\w/;" my_file.txt
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Lines containing e.g. a lone } will be removed with that. I'd do this:

perl -ni.bak -le "print if $_" my_file.txt
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update: Oops! choroba is right below. Heck...

perl -ni.bak -le "print if length $_" my_file.txt
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perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

The last line containing 0 and no newline would be removed :-)
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

Lines containing e.g. a lone } will be removed with that.

Oops, that's right, but I based the one-liner on the sample data shown by the OP, i.e. a file with a list of server names, which ought to contain some alphanumerical characters (and/or empty lines), not Perl or C code.

Perhaps a stricter version:

perl -ni.bak -e "print $_ unless /^[\n\s]+$/;" my_file.txt
[download]

But even this might also fail on some edge cases, the really right regex really depends on the actual content of the file being processed.

If there are only blank lines at the end of the file:

perl -lp00e1 file.txt
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