in reply to Re^4: How to ask user for file name and save the output to a new text file
in thread How to ask user for file name and save the output to a new text file

perl is human friendly; infact a comma is missing after the decalration of the lexical filehandle name:

open my $writehandle "+>", $filetowrite 

# must be

open my $writehandle , "+>", $filetowrite

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PS pay attention: while(<$writehandle>) will never work: the pointer is to the end of file when you try to reaad from that handle: You can use seek to rewind it but probalby it will be better another strategy: instead of writing to a file accumulate the output into an array.

Then you can foreach my $line (@out_array){ # do whatever you want...

PPS if you provide an example data you are grabbing and the expected output for sure some monk can suggest a better way to handle your data: I suspect you have a filehandle or two more than necessary..

L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

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Re^6: How to ask user for file name and save the output to a new text file
by mmazlan67 (Novice) on Jun 20, 2017 at 03:15 UTC

    Hi, thanks, i'll search and understand more on how to use 'seek'. Btw, your solutions really helps me alot. I'll try improving my script using 'seek'. Once again, thanks!!

[reply]
      Hello again mmazlan67,

      if you use seek you still go in direction of complexity while will be better to semplify your program flow filling a @results array.

      As general rule when you can avoid to read or to write to a file do it: filesystem is the sloooowest part of your PC and expose you to more errors.

      If I understand your needs you just need one file to read from: use it and close it as soon as possible.

      I propose below an example program very similar to what already showed: I need to guess about your data and so the regex part is surely to be reviewed (but see my comment about your regexes!).

      I also added a bit of debug to the screen and the mail composition using CDO.sys windows component: usig OLE object is not so funny but is better than piping a mail into an external program, imho.

      I wish you to learn something from my code and go to perldoc for everything you possibly do not understand like $0 $. $1 $2 ...

      have fun!

      # never forget the following!!!
use strict;
use warnings;
#  use diagnostics; # this can be skipped but is useful when starting
# if you want to send the mail using the win32 component CDO.sys you n
+eed:
use Win32::OLE;

# grab user input..
# ask for a file to read unless it was specified in the commandline
my $filetoread;
unless ($filetoread = $ARGV[0]){
  print "Enter a filename to read from:\n";
  $filetoread = <STDIN>;
  chomp $filetoread;
  # check if the file exists
  die "File [$filetoread] does not exists or cant be accessed" unless 
+-e $filetoread;
}

# use an array to accomulate the results
my @results;

open my $readhandle, '<', $filetoread or die "Unable to read [$filetor
+ead]!";

while (<$readhandle>){
      # your first regex is unuseful:
      # $_ =~ /^\s\s(\S+)*delay\s+(\S+)\s+(\S+)\ ....
      # you use () which are capturing groups in regexes and populate 
+$1,$2..
      # you never use them in your program!
      #
      # In your following regex you use:
      # -->my ( $name,$value ) = m/-name (\S+) (\S+)/;  #get the name 
+and value
      # this does NOT get name nor values
      # I try to guess your data and then i push in @results array
                    #set goes in $1 $2     $3               $4
      if ($_ =~ /\s+(\S+).*-name\s+(\S+)\s(\S+).*mode\s==\s(\S+)/){
      
          # print to console some useful info ($. is the current line 
+number)
          print "$filetoread:$. match the pattern given\n";
          # push into result array a composed string
          push @results, "$1 $2 $3 $4\n";
      }
      # print to console skipped lines
      else{
            print "skipping line $.\n";
      }
}
# always explicitally close filehandle: Perl will normally does the ri
+ght thing
# but it is safer to close them anyway (good habit)
close $readhandle;

# again someting useful to check: exit the program if nothing was foun
+d
unless (@results){
    print "Nothing found in file [$filetoread]\nexiting..\n";
    exit;
}
# if here, so there is someting to work with
print "Found ", @results, " useful lines\n";
# use the CDO.sys object via Win32::OLE to compose and create the mail
# something like (modified/untested) the following:

my $mail = Win32::OLE->new("CDO.Message");

$mail->{From}="$0\@yourloaclsystem.org";
$mail->{To}='destination@domain.org';
$mail->{Subject}="results from $0 ".scalar localtime(time);

# fill the body
foreach my $entry (@results){
         $mail->{TextBody}.=$entry;
}
my $conf =  Win32::OLE->new ("CDO.Configuration") ;
my $fields = $conf->{Fields};

$fields->{"http://schemas.microsoft.com/cdo/configuration/sendusing"}=
+2;
$fields->{"http://schemas.microsoft.com/cdo/configuration/smtpserver"}
+="your.usable.smtp.server.or.relayserver.org";
$fields->{"http://schemas.microsoft.com/cdo/configuration/smtpserverpo
+rt"}=25;

$fields->Update();

$mail->{Configuration} = $conf;
$mail->Send()|| warn Win32::OLE->LastError();

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      L*

      There are no rules, there are no thumbs..
      Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
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