You don't need to touch STDOUT actually, and you can simplify the file read:
my $stringified = '';
{
#Go into local slurp mode ..
local $/=undef;
open FH, "< ./demo.mail";
$stringified = <FH>;
close FH;


open (CMD_OUT, "/usr/lib/dovecot/deliver -f 
+test\@somedomain.com -d test\@mailtask.dom $stringified"|);
my $test = <CMD_OUT>;
print $test;
close CMD_OUT;
}

[download]


The 'local $/=undef' bit turns off the normal record separator (newline by default). So when the filehandle is read the data is slurped in as one record. The point of enclosing in {}'s is to localise the effect - outside the {}'s the default separator will be used.

You could also use the back-tick notation to run the shell command: 
my $test = `/usr/lib/dovecot/deliver -f 
+test\@somedomain.com -d test\@mailtask.dom $stringified`;

[download]
There are other ways of course. This is perl after all.

In reply to Re: Newbie: Pipe/STDIN Clarification by mrstlee
in thread Newbie: Pipe/STDIN Clarification by mpapet

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