I have the following subroutine:

sub email_warning {
    my $threshhold_value = $ARGV[0];
    my $current_load_avg = &run_sar();
    my $email_body = "15 minute load average of $current_load_avg has 
+equaled or exceeded the threshhold you specified: $threshhold_value";
    open (MAIL, "|mailx -s \"15 minute load average warning\" wentwort
+h\@localhost");
    # print $email_body;
    print MAIL $email_body;
    close MAIL;
}
[download]

The email body I receive contains only the part of $email_body up to and including the $current_load_avg variable. e.g. "15 minute load average of 4.01" and nothing after that. I'm guessing it has to do with mailx, because if I print the $email_body scalar, it looks fine. I'm perplexed.

UPDATE: OK, this is resolved. Toolic was right, printing $current_load_avg as a test printed it on a line by itself.

As it happens, that troublesome newline character was the only thing making the email send successful. When I chomped it, all the generated emails had null message bodies. I had to add a "\n" to the

print MAIL $email_body;

statement.

Thanks everyone for the help.