May 2008 - Darwin-dev - lists.apple.com

Re: Getting processor description from sysctl
by Terry Lambert 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Ah, but the structure and keys of the output are not documented, and AFAIK have changed somewhat over the ages. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On May 15, 2008, at 2:10 PM, Finlay Dobbie wrote: On Thu, May 15, 2008 at 10:08 PM, Jordan K. Hubbard <jkh(a)apple.com> wrote: On May 15, 2008, at 1:51 PM, Finlay Dobbie wrote: Is the format of output from commandline utilities guaranteed across software updates? I'm sure jkh has made statements to the effect that they are not :o) Unless a command-line utility is producing XML or some other format specifically designed and documented to be "machine readable", then the format is essentially whatever we say it is from release to release and there are no warrantees expressed or implied. Finlay is correct and Terry was over-simplifying things just a bit in that regard. lsof and ps are documented as producing machine parseable output, if the appropriate command line arguments are used; for lsof, this is "- F"; for ps, this is "-o". "system_profiler -xml" produces XML output; "system_profiler" without - xml is documented as producing colon separated key/value pairs, when queried within a single subhierarchy, which was the specific case under discussion (i.e. also machine parseable for the restricted case being discussed). Obviously, if a command doesn't have the necessary options, you are at more risk parsing its output -- but less risk than if you were to (for example) use sysctl-based data interfaces or grovel around in /dev/mem or /dev/kmem, with your code depending on kernel symbols and data structures not changing. They will change. You're right, that one defect of XML is the lack of tool-specific DTDs. You can parse output into an associative array, but you can't guarantee me that a key/value pair isn't going to go away from revision to revision, since there is no DTD to nail me to a cross of immutability. Thus the only thing you can really guarantee me is that the parsing code can be normalized and thus simplified. So, Finlay, what do you suggest as a more perfect solution to the problem? This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Terry Lambert 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Is the format of output from commandline utilities guaranteed across software updates? I'm sure jkh has made statements to the effect that they are not :o) -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On May 15, 2008, at 1:51 PM, Finlay Dobbie wrote: On Thu, May 15, 2008 at 9:39 PM, Terry Lambert <tlambert(a)apple.com> wrote: [snip about parsing output of system_profiler] It's just not that hard to do this sort of thing without resorting to interfaces that might break each time there's a software update. Now the original poster has two examples. Am I ever going to guarantee you an API that won't ever break? No. No one can; there is no one person who makes all the engineering decisions at Apple. All I can do is point you in a direction of less risk of you needing to do additional code maintenance in the future. This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Finlay Dobbie 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=WDEM0HiMX6lVe14M6Tkv6chifVwUkDaepUTuc4LWmAg=; b=As5HfN0JzgmjRKuFQgwdTjvcC4pzed3uP+jXd6sFt32G+YY1gfej54ekmBv6sXRoiDbopmFWJ+Zseo8GkNTYFdHc+R77wo3aR2UdJFMMwHFrYUTPaXYPqGPQSwAQ/SN8ePKY468aZ4ckzeBlpFxmssdjx+iVh+UCs9ieuu2Y0q0= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=aXQ4DJYvx7w+eWdvbTdQBGQIF7Krybrqj/qAvqBG3MaGADOS50j40vL9In3YsVn/Mjadp4aq/hWK42zCwH7h4TFqTl+KYfNzeJgSGFffAATJuC43yI0v64RUwSEDskZb7DKGQXf/8kkNsnXXQmRg4Bp00Ytj8/PedlmpChU/+kA= On Thu, May 15, 2008 at 10:08 PM, Jordan K. Hubbard <jkh(a)apple.com> wrote: > > On May 15, 2008, at 1:51 PM, Finlay Dobbie wrote: > > > > Is the format of output from commandline utilities guaranteed across > > software updates? I'm sure jkh has made statements to the effect that > > they are not :o) > > > > Unless a command-line utility is producing XML or some other format > specifically designed and documented to be "machine readable", then the > format is essentially whatever we say it is from release to release and > there are no warrantees expressed or implied. Finlay is correct and Terry > was over-simplifying things just a bit in that regard. Ah, but the structure and keys of the output are not documented, and AFAIK have changed somewhat over the ages. -- Finlay _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Jordan K. Hubbard 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 15, 2008, at 1:51 PM, Finlay Dobbie wrote: Is the format of output from commandline utilities guaranteed across software updates? I'm sure jkh has made statements to the effect that they are not :o) - Jordan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Unless a command-line utility is producing XML or some other format specifically designed and documented to be "machine readable", then the format is essentially whatever we say it is from release to release and there are no warrantees expressed or implied. Finlay is correct and Terry was over-simplifying things just a bit in that regard. This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Finlay Dobbie 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=JNK4Ns3PE91RGSthrMPhdSJXouV4pmj/p5siaT9q86s=; b=HLtWIDWSQ1wSWqYXKgkVWV/nFrwruwTsLPe6eoWLRgOmtJzRL3AZ29r3wnd3h270eMcaa71OXJiv3/f+Vhjt3uJM0S0OXpGlrgq3anIWgIzjJZFpvlOdwV2eDuIJYVQ/RTqI0z3NcaYOV8jzbK/YIE+qWoo8qFObJpbExykMjl0= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=YoixZ9ThNmNIpTAKrcNu1IzHbt/N9u+OWNFwYq1X1HvZRJmERfPZeVdCxN1vohs2T1Xqxuew/Esvip9zscIccoHgFm9Ey+Pio0g9uPHQCRmqagEnmif5YqNTf8/LtRJURw32Aophtg8Oll/uhpRnnj3+gHJENnWZeRLbBHDGMS0= On Thu, May 15, 2008 at 9:39 PM, Terry Lambert <tlambert(a)apple.com> wrote: [snip about parsing output of system_profiler] > It's just not that hard to do this sort of thing without resorting to > interfaces that might break each time there's a software update. Now the > original poster has two examples. Is the format of output from commandline utilities guaranteed across software updates? I'm sure jkh has made statements to the effect that they are not :o) -- Finlay _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Terry Lambert 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 08-05-14, at 21:41, Mike wrote: Maybe: system_profiler -xml SPHardwareDataType Or if you want to avoid Objective C, parsing XML, or using TCL: #define CMD "/usr/sbin/system_profiler SPHardwareDataType" #define TAG "Processor Name: " #define UNK "UNKNOWN" char * get_cpu_name(void) { static char cpu_name[128] = UNK; char buf[sizeof(cpu_name)]; char *p; char *q; FILE *fp; -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On May 14, 2008, at 11:26 PM, Philip Aker wrote: System Profiler provides the processor name, so there must be a way to get it. For example on the MacBook it reports: Processor Name: Intel Core 2 Duo In C, not from a shell script. [ ... cute TCL thing elided ... ] /* Cache results for subsequent calls */ if (!strcmp(UNK, cpu_name)) { if ((fp = popen(CMD, "r")) != NULL) { while (fgets(buf, sizeof(buf), fp) != NULL) { if ((p = strstr(buf, TAG)) != NULL) { p += strlen(TAG); if ((q = strchr(p, '\n')) != NULL) *q = 0; strcpy(cpu_name, p); break; } } fclose(fp); } } return(cpu_name); } ...obviously, this could also be done associatively, with or without the TCL, to capture all the information in a single run of system_profiler so that it could be used as separate name/value pairs, and you could look up the value for any name. It's just not that hard to do this sort of thing without resorting to interfaces that might break each time there's a software update. Now the original poster has two examples. This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Philip Aker 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 08-05-14, at 21:41, Mike wrote: Maybe: system_profiler -xml SPHardwareDataType /* sysprof.c */ #include <CoreFoundation/CoreFoundation.h> #include <Tcl/tcl.h> // :-) Philip Aker echo astwta@lvpc.dslh@nl | tr a-z@. p-za-o.@ Sent from my SE/30 _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… System Profiler provides the processor name, so there must be a way to get it. For example on the MacBook it reports: Processor Name: Intel Core 2 Duo In C, not from a shell script. int main( int argc, char *argv[] ) { #pragma unused( argc, argv ) int err = noErr; Tcl_Interp *interp = Tcl_CreateInterp(); Tcl_Obj *cmd = Tcl_NewStringObj( "exec /usr/sbin/system_profiler -xml SPHardwareDataType", -1 ); if( Tcl_EvalObj( interp, cmd ) == TCL_OK ) { int length = 0; unsigned char *bytes = Tcl_GetByteArrayFromObj( Tcl_GetObjResult( interp ), &length ); CFDataRef data = CFDataCreate( kCFAllocatorDefault, bytes, length ); if( data != NULL ) { CFArrayRef array = CFPropertyListCreateFromXMLData( kCFAllocatorDefault, data, kCFPropertyListMutableContainersAndLeaves, NULL ); if( array != NULL ) { CFDictionaryRef dict = (CFDictionaryRef)CFArrayGetValueAtIndex( array, 0 ); CFArrayRef items = CFDictionaryGetValue( dict, CFSTR( "_items" ) ); CFDictionaryRef details = CFArrayGetValueAtIndex( items, 0 ); CFStringRef cpu_type = CFDictionaryGetValue( details, CFSTR( "cpu_type" ) ); CFShow( cpu_type ); CFRelease( array ); } CFRelease( data ); } } return err; } This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Terry Lambert 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com "machdep.cpu.brand_string" (use sysctlbyname(), please). -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On May 14, 2008, at 8:28 PM, Mike wrote: Terry Lambert wrote: On May 14, 2008, at 7:28 PM, Mike wrote: Is there a way to get the description of the processor(s) using sysctl. I am interested in the specific processor name, not the family name. For example "Northwood", not "i386" or "x86". No. We care about the family and the capability bits, not the Intel marketing name for it. The first lets us grade binaries, and th second lets us write software that avoids attempting to use capabilities not present on a specific CPU. -- Terry I am not attempting to use this info to determine capabilities of the specific CPU. I need to write a system-profiler like feature and I need the name of the processor, not just the family. System Profiler provides the processor name, so there must be a way to get it. For example on the MacBook it reports: Processor Name: Intel Core 2 Duo Oh, you gave an example of "Northwood", which I don't expect you'll ever see. If you just want to report what system_profiler reports, the easiest way is to do what Philip Aker suggested, and invoke the command line version of system_profiler and read its output. If you are OK with less specificity, and insist that it be a sysctl, then: I expect you can get this same information from issuing the CPUID instruction various ways, which is how we fill out the capability bits. Remember that not checking the capability bits, and assuming that some marketing name means a feature is usable does not mean the feature is usable. For example, it's possible with a boot argument to disable Altivec on G4 and G5 based machines, and Intel CPUs have similar capabilities, so not looking at the capability bits means you might be trying to use some hardware feature that has been disabled for some reason (e.g. power management, etc.). This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Mike 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.14 (Macintosh/20080421) On 08-05-14, at 20:28, Mike wrote: Maybe: system_profiler -xml SPHardwareDataType Philip Aker echo astwta@lvpc.dslh@nl | tr a-z@. p-za-o.@ Sent from my SE/30 In C, not from a shell script. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Philip Aker wrote: Terry Lambert wrote: On May 14, 2008, at 7:28 PM, Mike wrote: Is there a way to get the description of the processor(s) using sysctl. I am interested in the specific processor name, not the family name. For example "Northwood", not "i386" or "x86". No. We care about the family and the capability bits, not the Intel marketing name for it. The first lets us grade binaries, and th second lets us write software that avoids attempting to use capabilities not present on a specific CPU. -- Terry I am not attempting to use this info to determine capabilities of the specific CPU. I need to write a system-profiler like feature and I need the name of the processor, not just the family. System Profiler provides the processor name, so there must be a way to get it. For example on the MacBook it reports: Processor Name: Intel Core 2 Duo This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Philip Aker 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 08-05-14, at 20:28, Mike wrote: Maybe: system_profiler -xml SPHardwareDataType Philip Aker echo astwta@lvpc.dslh@nl | tr a-z@. p-za-o.@ Sent from my SE/30 _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Terry Lambert wrote: On May 14, 2008, at 7:28 PM, Mike wrote: Is there a way to get the description of the processor(s) using sysctl. I am interested in the specific processor name, not the family name. For example "Northwood", not "i386" or "x86". No. We care about the family and the capability bits, not the Intel marketing name for it. The first lets us grade binaries, and th second lets us write software that avoids attempting to use capabilities not present on a specific CPU. -- Terry I am not attempting to use this info to determine capabilities of the specific CPU. I need to write a system-profiler like feature and I need the name of the processor, not just the family. System Profiler provides the processor name, so there must be a way to get it. For example on the MacBook it reports: Processor Name: Intel Core 2 Duo This email sent to site_archiver(a)lists.apple.com

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