Perl

Enumerate the Header Fields of an Email

Demonstrates the read-only Chilkat Email.NumHeaderFields property together with GetHeaderFieldName and GetHeaderFieldValue to enumerate every header field. Indexing is zero-based, so fields run from 0 to NumHeaderFields - 1. Repeated header fields (a field name that appears more than once) are counted separately. This example builds a small email and prints each header field.

Background: A header field is a single Name: value line at the top of a MIME message. The same field name can legitimately appear multiple times — for example, a message can carry several Received lines, one added by each mail server it passed through. That is why enumerating by index (rather than looking up by name) matters: it lets you see every occurrence in the order it appears.

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Perl

use chilkat();

#  Demonstrates the read-only Email.NumHeaderFields property and enumerating each
#  header field by zero-based index using GetHeaderFieldName and GetHeaderFieldValue.

$email = chilkat::CkEmail->new();
$email->put_Subject("Header field enumeration");
$email->put_From('mary@example.com');
$email->AddTo("Joe",'joe@example.com');

$n = $email->get_NumHeaderFields();
print "NumHeaderFields = " . $n . "\r\n";

for ($i = 0; $i <= $n - 1; $i++) {
    print $email->getHeaderFieldName($i) . ": " . $email->getHeaderFieldValue($i) . "\r\n";
}