October 2010 - launchd-dev - lists.macosforge.org

Programmatic interface to launchctl and some other questions, OS X 10.5
by eveningnick eveningnick 04 Nov '10

04 Nov '10

Hello I am writing a Cocoa application, that installs and launches an agent (and, if needed - stops that agent, and uninstalls it). This agent is supposed to watch for a launch of another certain application, and if it encounters such an event, it launches some process itself. I am wondering, how could i programmatically register (launchctl's load operation), start (launchctl's start), stop and unload the agent, doing these operations from my Cocoa application? The target operating systems are Mac OS X 10.5 and 10.6. Having searched through the Internet i have found ServiceManagement.h (that allows, as i understand, installing application into /Library/LaunchAgents, even if the application that called SMJobBless/SMJobSumbin was non-root). I am not very "familiar" with OS X ideas. As i understand, when a user doubleclicks my Cocoa application's bundle, the application is launched with non-root privileges, which means i can't "launchctl load" my agent into /Library/LaunchAgents - i can only do that with /Users/username/Library/LaunchAgents directory. But unfortunately this ServiceManagement API is supported only since OS X 10.6 Also there's a /usr/include/launch.h file, which provides some kind of API, but i've no idea how to use it, and i am not sure if it gives any means to load/start/stop/unload agents. Maybe i could use it somehow? Most suggestions about programmatical management of agents are about calling "[NSTask launchProcess:@"launchctl {operation} {label}"]". If there is no other better choice, i'd take it, but i am a little confused about privileges - i won't be able to install an agent to /Library/LaunchAgents, will I?. I'm sorry if i'm saying nonsense, but if i call "[NSTask launchProcess:@"sudo launchctl {operation} {label}"]" will it count as a launch from root, or this trick works only if its done in a terminal? how can i determine, if my agent is running or not, from my Cocoa application? and how could i determine if it's registered (loaded, in terms of launchctl) or not? Calling [NSTask launchProcess:@"launchctl list | grep com.mycompany.myagent"] and then parsing the returned string seems wrong to me :/. Is it really the only choice? I was also searching for the info on how to launch a process, that is a console one (Gui-less). Most suggestions are about using launchd instead of fork/exec-ing it. How is it done usually? Should i necessarily create and save that *.plist to the /Users/username/Library/LaunchAgents/ directory and then call that "[NSTask launchProcess:@"sudo launchctl {operation} {label}"]"?, first with "launchctl load" and second with "launchctl start"? OS X 10.6's ServiceManagement.h API seems to support launching of processes without first copying plist to the one of the "agents'" directories, but again it's only OS X 10.6. Sorry for so many questions :) And Thanks a lot for the response!

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What does launchd do, if the application in "Program" section was not found?
by eveningnick eveningnick 27 Oct '10

27 Oct '10

If in ~/Library/LaunchAgents/com.myprogram.plist i define "RunAtLoad: TRUE", but specify non existing application as "Program" parameter, what scenario does launchd follow? Does it just skip that plist file? Or does it try to find the program binary file in some other directory? what impact does it have on the speed of the system boot? Thanks

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Re: [launchd-dev] Programmatic interface to launchctl and some other questions, OS X 10.5
by Rainer Brockerhoff 26 Oct '10

26 Oct '10

At 05:49 -0700 26/10/10, launchd-dev-request(a)lists.macosforge.org wrote: >Date: Tue, 26 Oct 2010 10:13:09 +0100 >From: "Quinn \"The Eskimo!\"" <eskimo1(a)apple.com> >Message-ID: <AAB6BEB9-F4AF-4B93-A3D6-E49DB5C0ECC2(a)apple.com> > >On 26 Oct 2010, at 03:55, Jerry Krinock wrote: > >> On 2010 Oct 25, at 18:01, eveningnick eveningnick wrote: >> >>> Also there's a /usr/include/launch.h file, which provides some kind of >>> API, but i've no idea how to use it, and i am not sure if it gives any >>> means to load/start/stop/unload agents. Maybe i could use it somehow? >> >> Anyone know what he's talking about? > >The routines in <launch.h> provide necessary services for launchd jobs (daemons and agents). Specifically, a launchd job uses this API to check in with launchd. See SampleD for an example of this. > ><http://developer.apple.com/library/mac/#samplecode/SampleD/> > >If you need to manipulate the launchd state, you should use Service Management (if it's available and does what you want) or simply fork/exec launchctl. And yes, it is both sad and a chore )-: As a footnote to Quinn's reply, check out my post about using the launch.h API to check if your agent is running: http://brockerhoff.net/blog/2009/02/02/cocoa-musings-pt-3/ This does work under 10.5. HTH, -- Rainer Brockerhoff <rainer(a)brockerhoff.net> Belo Horizonte, Brazil "In the affairs of others even fools are wise In their own business even sages err." Blog: http://brockerhoff.net/blog

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How to update tool after using SMJobBless() ?
by Thomas Clement 05 Oct '10

05 Oct '10

>> On Oct 5, 2010, at 6:24 AM, Thomas Clement wrote: >> >> Hello, >> >> Once I have installed my privileged helper tool using SMJobBless(), how do I go about updating the tool? >> Calling SMJobBless() again does not seem to overwrite the launchd plist nor the helper executable. >> >> Thomas, > > ServiceManagement will check the CFBundleVersion of the tool and, if it's the same (and if the code identity of the existing one is valid), will not overwrite it. > -- > Damien Sorresso Right, it does work as described :) However I'm getting these logs: kernel CODE SIGNING: cs_invalid_page(0x1005cf000): p=1176[launchdadd] clearing CS_VALID kernel CODE SIGNING: cs_invalid_page(0x100000000): p=1177[com.myapp] clearing CS_VALID Am I doing something wrong? Thomas

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How to update tool after using SMJobBless() ?
by Thomas Clement 05 Oct '10

05 Oct '10

Hello, Once I have installed my privileged helper tool using SMJobBless(), how do I go about updating the tool? Calling SMJobBless() again does not seem to overwrite the launchd plist nor the helper executable. Thanks, Thomas

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Running my application on event: another application's start
by eveningnick eveningnick 04 Oct '10

04 Oct '10

Hello! I am no sure if it is a right list to post this message. Sorry if not :) How could i implement the subj? What i need to do - is to launch a "plugin process" (ordinary cocoa application, written by me) when the host application (ordinary carbon application, Microsoft Word) starts, i.e. when the user launches it from the dock, or doubleclicks on any *.docx icon in finder. On other lists I've been told to use launchd, but it turns out that Launchd doesn't support events like watching another application start, so i am curious if someone has implemented something similar, and how can it be implemented. "Who" in OS X can give me a notice, that a new process with name "Microsoft Word" has been launched? So far i see the solution like an agent, that is started with the system start, and which somehow pulls "ps" command in forevercycle, watching for "Microsoft Word" to appear in the list. If it word is started - this agent starts my plugin. If not - it continues pulling "ps". Maybe there's more sane way to perform that, something more "neat" and something that wouldn't irritate user. Thanks a lot for any advice George

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