http://qs1969.pair.com?node_id=256849

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

OK, Spank me. This question is not quite related to perl, but i know how inteligent you guys all are, and i would realy appreciate your input. I have my main mailbox file at /var/mail/james which when i open it, is simply a plain text file containing a few e-mails, and i have a backup of my file before my machine went down, which i have put at /root/james. I want to merge these two files together i.e put the contents of /root/james into the file /var/mail/james, is there a way to merge these two?

Replies are listed 'Best First'.
Re: Not Quite perl...
by Limbic~Region (Chancellor) on May 09, 2003 at 13:23 UTC
    Anonymous Monk,
    While smitz has already pointed out you can do:

    cat /root/james >> /var/mail/james

    You can also do this with Perl. 

    #!/usr/bin/perl -w
use strict;
open (MBOX1,"/root/james") or die "unable to open mailbox : $!";
open (MBOX2,">>/var/mail/james") or die "unable to append to mailbox :
+ $!";
select MBOX2;
while (<MBOX1>) {
    print;
}

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    Of course - don't do this - you would be in a race condition. If any other process were writing to the second mailbox, information would become inter-leaved. Yes, there is locking, but I do not believe Sendmail respects locks on mailboxes.

    You could always check CPAN - Mail::Box::Mbox and Mail::Box were both updated yesterday 8 May 03.

    Cheers - L~R

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Re: Not Quite perl...
by smitz (Chaplain) on May 09, 2003 at 13:21 UTC
    If /var/mail/james is empty or doesnt exist
    • cat /root/james > /var/mail/james
    If not
    • cat /root/james >> /var/mail/james

    This code is untested, and I'm a windows kind of a guy, so test this on some expendable text files first :-)

    Smitz
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Re: Not Quite perl...
by crouchingpenguin (Priest) on May 09, 2003 at 16:56 UTC

    As Limbic~Region pointed out, Mail::Box is perfect for this sort of thing. Here is an example (assuming mbox format):

    #!/usr/bin/perl
use strict;
use warnings;
use diagnostics;
use Mail::Box::Manager;

my ($folder1,$folder2,$folder3) = @ARGV;

my $mgr = Mail::Box::Manager->new( folderdir => [ '.' ] );
my $f1 = $mgr->open(folder => $folder1, ) or die $!;
my $f2 = $mgr->open(folder => $folder2, ) or die $1;
my $f3 = $mgr->open(folder => $folder3, create => 1, access => 'rw', )
+ or die $!;

foreach my $msg ( $f1->messages(),$f2->messages() ){
    $msg->copyTo($f3) if $msg;
}
# or $mgr->copyMessage($f3, ($f1->messages(),$f2->messages()) );

$mgr->closeAllFolders();

1;

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    cp
    ----
    "Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic."
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Re: Not Quite perl...
by smitz (Chaplain) on May 09, 2003 at 13:12 UTC
    man cat
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      huh? I think it was a cat.
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Re: Not Quite perl...
by teabag (Pilgrim) on May 09, 2003 at 13:29 UTC
    Whack! (sound of a profound spanking)
    Hmm, Im not sure about the date sorting so I would do it like this to be sure:
    cat /var/mail/james/mailfile >>/root/james/oldmailfile

    then copy it to your /var/mail/james/mailfile
    Archive the old /var/mail/james/mailfile just be be sure before you copy it there ;)

    Teabag
    Sure there's more than one way, but one just needs one anyway - Teabag

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