Zig

Rename Email Attachments After Adding

Demonstrates how to rename email attachments after adding but before sending. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    const mailman = try chilkat.MailMan.init();
    defer mailman.deinit();

    mailman.setSmtpHost("smtp.my-mail-server.com");
    mailman.setSmtpUsername("MY_SMTP_USERNAME");
    mailman.setSmtpPassword("MY_SMTP_PASSWORD");
    mailman.setSmtpSsl(true);
    mailman.setSmtpPort(465);

    const email = try chilkat.Email.init();
    defer email.deinit();

    email.setSubject("This is a test");
    email.setBody("This is a test");
    email.setFrom("Chilkat Support <support@chilkatsoft.com>");
    try email.addTo("Chilkat Admin", "admin@chilkatsoft.com");
    // To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

    // Add some attachments.
    // The AddFileAttachment method returns the value of the content-type it chose for the attachment.
    var content_type: [:0]const u8 = email.addFileAttachment(alloc, "qa_data/jpg/starfish.jpg") catch {
        std.debug.print("{s}\n", .{try email.getLastErrorText(alloc)});
        return;
    };

    content_type = email.addFileAttachment(alloc, "qa_data/pdf/fishing.pdf") catch {
        std.debug.print("{s}\n", .{try email.getLastErrorText(alloc)});
        return;
    };

    // If we save the email to a .eml, we can examine in a text editor.
    email.saveEml("qa_output/e1.eml") catch {
        std.debug.print("{s}\n", .{try email.getLastErrorText(alloc)});
        std.debug.print("Failed to save .eml\n", .{});
        return;
    };

    // We see the following in the e1.eml
    // Notice that Chilkat replaced the full path with just the filename.
    // The full local path is not part of the email that gets sent..

    // ...
    // --------------020807050607070004010609
    // Content-Type: image/jpeg; name="starfish.jpg"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="starfish.jpg"
    //
    // ...
    // --------------020807050607070004010609
    // Content-Type: application/pdf; name="fishing.pdf"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="fishing.pdf"
    // ...

    // Before sending, each filename can be changed within the email object.
    // For example:
    try email.setAttachmentFilename(0, "orange_starfish.jpg");
    try email.setAttachmentFilename(1, "tuna_fishing.pdf");

    // Look at the new MIME source of the email in a  text editor...
    email.saveEml("qa_output/e2.eml") catch {
        std.debug.print("{s}\n", .{try email.getLastErrorText(alloc)});
        std.debug.print("Failed to save .eml\n", .{});
        return;
    };

    // You'll see this:

    // ...
    // --------------020807050607070004010609
    // Content-Type: image/jpeg; name="orange_starfish.jpg"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="orange_starfish.jpg"
    //
    // ...
    // --------------020807050607070004010609
    // Content-Type: application/pdf; name="tuna_fishing.pdf"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="tuna_fishing.pdf"
    // ...

    // Send the email with the updated filenames..
    mailman.sendEmail(email) catch {
        std.debug.print("{s}\n", .{try mailman.getLastErrorText(alloc)});
        return;
    };

    mailman.closeSmtpConnection() catch {
        std.debug.print("Connection to SMTP server not closed cleanly.\n", .{});
    };

    std.debug.print("Mail with attachments sent!\n", .{});
}