OSX: No printing for CUPS

OSX: CUPS No printing problem yesterday I met a strange problem, a new VP machine, he told me that he could not print, after the print operation is complete, the printer does not print, the printer disappears after it turns out to be normal, and the machine does not have any error information. In general, this problem is well solved. It is nothing more than a re-installation after deletion, but this case is extraordinary. You can imagine that the simple method doesn't work. Try again: using different protocols for installation (Bonjour, ipp, lpd, Socket, etc.), it doesn't help; fix disk permissions and reset the printing System (in Print & Fax of System Preference). The problem persists. No progress has been made in the CUPS webpage management interface. About an hour later, the AP was impatient and asked if I could use its laptop. I said, ah, yes, I was busy. I have no time to check it carefully, you can get it back first. If you have time, you can get it back. Close the lid of the notebook around him and hand it to him. It's easy to make him feel that this problem will be solved soon. After he leaves in a hurry, I keep thinking about this. In the afternoon, he came back and said, "This is yours. I went out all afternoon. I saw it at, and I only had 2 hours at most. At the same time, I also needed to update the software and face other sudden events, I don't want to work overtime for his "small problem". It's best to do it as soon as possible, or else "Shame. According to the preliminary work, it is likely that the formation of the CUPS system/program is a problem. CUPS is the core and basis of the OS x system printing system, and it comes with OS X, there is almost no update installation package available on the Internet (there are related packages on cups.org, but it says We are no longer providing binaries for Mac OS x since newer releases ofCUPS are not generally compatible with prior releases of Mac OS X .), in fact, even if there is, do not dare to use. I really don't want to mirror the entire system, because the AP just got the machine for one week, took some special work with him, and gave him the admin permission, he moved all the data to the new machine and made another data transfer? I really don't want to do this. It's a last resort. Carefully check the logs of cups, in/var/log/cups/error_log, you can see a sentence similar to "/usr/libexec/cups/backend/ipp failed" or "/usr/libexec/cups/backend/ dnssd failed "and other error messages, this information varies depending on the protocol used by the printer. There are some such problems on the Internet, some of which are caused by Paused, some of which are solutions for 10.6.x, and others are not solved at all, these have little to do with this time. Since it is a problem in backend, let's take a look at the content. At first, the dnssd, http, ipp, lpd, smb, and socket files are all files and the file size is 37. After the disk permission is fixed, it becomes like the figure below, that is, they all point to the pa6hook connection. Does the original OSX system look like this? Compare the user permissions of another machine, for example (note that the user permissions are not displayed correctly .), obviously, the original system is no longer connected. In fact, those connections are in 10.7.2 (my current version) and earlier versions. The new version is not, directly copy the Protocol program here. In addition, the size of each protocol program file is incorrect. I don't know what the VP has installed. I changed this. Recovery is simple, but you must stop the cups service and immediately start the system after the replication. Fortunately, a tough problem is solved, so you can rest assured that you can go home to cook for your child. In addition, the figure above is 10.7.4, as shown in Figure 10.8.2: