rajyalakshmi has asked for the wisdom of the Perl Monks concerning the following question:

I have text file ,results.txt which has 2 things:

1.a newline character

2.a string "hello"

The following script of mine opens the results,reads each line .If it finds for the the string "hello", it sends a mail.If it does not find "hello". it does nothing.But the problem the mail is sent for both cases.Can you please figure whats the problem in the foll in script:

#!/usr/bin/perl
use MIME::Lite;
$pattern ='hello';

    my $msg = MIME::Lite->new(
    From    => 'rajyalakshmi.bangar@eternoinfotech.com',
    To      => 'bangar.rajyalakshmi@gmail.com',
    Type    => 'multipart/mixed',
    Subject => "Fetch issues as on $dateFile'",
);
$msg->attach(
    Type     => 'TEXT',
    Data     => "Hi,Please find attachement for Fetch issues as on '$d
+ateFile'",
);

$msg->attach(
    Type     => 'text',
    Path     => 'results.txt',
    Filename => 'results.txt',
);

#sysopen($FILE,$filepath,o_RDWR) or die "could find the file";
open FILE, "<results.txt" or die "Can't open results output file: $!";
while (my $line=<FILE>)
        {
        if($line=~m/\b$pattern/)
                {
                print " match";
                $msg->send;
                 }
       }

[download]

The mail is send for both foll conditions:

  1. if($line=~m/\b$pattern/)
  2. if($line!~m/\b$pattern/)

ie:ideally if match is found and the conditon is if($line!~m/\b$pattern/),the mail should not be sent

But if remove the new line character from the results.txt,the conditions work fine

Replies are listed 'Best First'.
Re: problem while searching for a pattern in a file
by cdarke (Prior) on Mar 24, 2010 at 09:05 UTC
    Your file is a strange format, so I created it programtically, if this is incorrect then please say so. I also simplified the code for these purposes, removing the email components:
    #!/usr/bin/perl
use strict;
use warnings;

my $pattern ='hello';

open (my $fh, '>', 'results.txt') or die "results.txt: $!";
binmode $fh;
print $fh "\nhello";
close $fh;

open FILE, "< results.txt" or die "Can't open results output file: $!"
+;
while (my $line=<FILE>)
{  
    if($line=~m/\b$pattern/)
    {
        print " match: <$line>";
    }
}

close FILE;

    [download]
    This matched "hello" as expected, just once. I suggest that maybe your file is not in exactly the format you say.
    You might like to display it using, for example od -xc results.txt if you are on UNIX/Linux.

    By the way, you are taking a risk running code without warnings and strict set. For example, in the commented out sysopen the flags should be O_RDWR (assuming you use Fcntl;), not o_RDWR, which you won't pickup.
[reply]
[d/l]
[select]
Re: problem while searching for a pattern in a file
by kiruthika.bkite (Scribe) on Mar 24, 2010 at 08:18 UTC
    Hi,
    I have executed your program in my system.It sent the mail only if the pattern get matched.
    I have tested your code with the following input.

    Input

    contents of results.txt
    \n
    \n
    \n
    This is testing

    In this case mail didn't send.

    And,
    if($line!~m/\b$pattern/)

    This condition will match the pattern other than "hello".
    So when newline is encountered this condition will get true.(\n!="hello").
    So in this case also mail will send.
[reply]

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