Create PrintJob via URL

[BjoernDroste365]

Hello,

is there a way to print something, e.g. a PDF, to CUPS via an URL?

I mean, the CMD line for printing “lp -d MyPrinter srv/MyDocument.pdf” works fine, and when the first print job is complete, I can also print the job using the CUPS Web-UI (http://IP-ADDRESS:631/printers/MyPrinter).

But how do I send a print job via URL? If I use http://IP-ADDRESS:631/printers/MyPrinter, I get the HTML code of the web page from the printer as a response.

The connection between CUPS and the printer shouldn't matter, because in my opinion the correct request is the problem. Or is it not possible to send a request via URL (POST)?

[michaelrsweet]

May I suggest you read the How to Use the Internet Printing Protocol e-book?

[BjoernDroste365]

yes, but for example http://IP-ADDRESS:631/ipp/print/MyPrinter doesn't work either.
But with this request I get a “not found” response.

The “IP-ADDRESS” is the address of the CUPS server. The printer is connected to CUPS via socket, but as I said, that shouldn't matter.

And anyway, it looks like all the URLs in the e-book are for printers used directly, and not with CUPS.

[BjoernDroste365]

@michaelrsweet

I just want to know what the equivalent of the CMD line “lp -d MyPrinter srv/MyDocument.pdf” is for a URL if the printer itself is not an IPP printer and is connected to CUPS via socket.

Is this too complicated to describe? I mean, your link explains how to do this via IPP printers. But I don't have an IPP printer.

[michaelrsweet]

The "lp" command ALWAYS connects to the local cupsd and sends IPP Create-Job and Send-Document requests to the specified print queue (at ipp://localhost/printers/PRINTERNAME for CUPS 1/2.x), which then goes through the filter pipeline and backend ("man 7 filter" and/or look at the CUPS documentation) to convert the print files to a format the printer can accept and send it to the printer (however it is connected).

[BjoernDroste365]

@michaelrsweet

So if I use the link http://CUPS-IP-ADDRESS:631/printers/MyPrinter, I simply have to send these operations (copy-paste)? The content type should be application/ipp, right?

the ipp-attribute for the printer uri, is it the socket uri, or the http://CUPS-IP-ADDRESS:631/printers/MyPrinter uri?

[michaelrsweet]

You need to use IPP URIs, so use "ipp://CUPS-IP-ADDRESS-OR-HOST-NAME:631/printers/MyPrinter" for the printer-uri attribute. Again, the How-To guide I linked to is a good place to start, and just focus on talking to CUPS and not directly to your printer.

Depending on what language you are using and environment, you may be able to use existing libraries to create your requests and parse the responses.

[BjoernDroste365]

@michaelrsweet

I solved it.

My problem was that the printer I had registered in CUPS was not authorized for external commands. The only thing I had to do was set the property printer-is-shared to true to authorize the printer.

[kundan1293]

Hi, thanks for the sharing. I am also facing the same issue. Could you please share little more details about the what are required data need to send in api request and where need to set the printer-is-shared to true ? Or could you please share any document reference where I can see ?

[BjoernDroste365]

I use the CUPS server via a Java application with the package:

<dependency>
      <groupId>de.gmuth</groupId>
      <artifactId>ipp-client</artifactId>
</dependency>

There, I only need the IP address and the data for printing:

//Example
public static void main(String[] args) throws Exception {
    IppPrinter ippPrinter = new IppPrinter("ipp://IP-ADDRESS:631/printers/MyPrinter");
    ippPrinter.printJob(new FileInputStream("PathToFile"));
}

To configure the CUPS server, you must execute the following command where the CUPS server is running. The printer should then be visible externally.
lpadmin -p PrinterName -o printer-is-shared=true

[kundan1293]

Thanks for the sharing. So, similar we can achieve through http ?

[BjoernDroste365]

In my case, it worked with a local CUPS server. Depending on how the CUPS server is configured, it may not accept HTTP for security reasons.