Perl Programming Examples: Email, Encryption, Zip, HTTP, XML, FTP

Perl function syntax, Perl function declaration and arguments syntax.

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Question:
How do I write a function in Perl?

Answer:
An example of a Perl function is provided below. This one is called with 4 arguments: $crypt, $key, $clearBytes, and $expectedAnswer. The point of this example is not to understand what this particular Perl function accomplishes, but rather to see a real-world example of the Perl function syntax.

sub blowfishECB {
	
   my($crypt, $key, $clearBytes, $expectedAnswer) = @_;
   
    
    # Set the secret key
    $crypt->SetEncodedKey($key, "hex");
    
    # Get the unencrypted data as binary data.
	$unencryptedData = new chilkat::CkByteData();
    $crypt->Decode($clearBytes, "hex",$unencryptedData);
    
	$encryptedHexString = new chilkat::CkString();
    $crypt->EncryptBytesENC($unencryptedData,$encryptedHexString);
    
    # Chilkat padded to a multiple of 16 bytes, so we discard the padding.
    # (In this case, Chilkat added 8 NULL bytes to the original 8 bytes of data,
    # so we drop 16 characters - the hex encoding uses 2 characters per byte.)
    $encryptedHexString->shorten(16);
    
    # Return a string that will be added to our output for visual verification.
    return $encryptedHexString->getString() . " should equal " . $expectedAnswer;
}