October 2006 - Darwin-dev - lists.apple.com

Re: [APPL:DarwinDev] Re: cp -f option
by Jay A. Kreibich 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Mutt/1.4.2.1i On Wed, Oct 11, 2006 at 01:12:37PM -0700, Jeffrey Ellis scratched on the wall: > > on 10/11/06 6:32 AM, darwin-dev-request(a)lists.apple.com at > darwin-dev-request(a)lists.apple.com wrote: > > >> Sorry for being dense. Not sure I understand exactly what this does. Can > >> someone explain this...? > >> > >> -f For each existing destination pathname, remove it and create a new > >> file, without prompting for confirmation regardless of its > >> permissions. > >> > >> Doesn't cp do this by default unless you use -i or -n ...which this > >> overrides? > > > > No. > > > > $ cd /tmp > > $ cp /dev/null t > > $ chmod 600 t > > $ cp /dev/null t > > $ chmod 0 t > > $ cp /dev/null t > > cp: t: Permission denied > > $ cp -f /dev/null t > > $ > > > > -s > > Hi, Peter-- > > Sorry, but could you please explain this output step by step? I'm not sure I > really get what's happening... The whole point of "-f" is expressed in the last four words of the description: "....regardless of its permissions." "Its", in this case, is the file that is about to be overwritten. That's the difference between the default "no option" behavior of cp and "-f". cp, by default, will not overwrite a file if the user lacks write permission. "-f" will overwrite such a file, assuming the user has permission to grant themselves write permission. -j -- Jay A. Kreibich | CommTech, Emrg Net Tech Svcs jak(a)uiuc.edu | Campus IT & Edu Svcs <http://www.uiuc.edu/~jak> | University of Illinois at U/C _______________________________________________ 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: cp -f option
by Jeffrey Ellis 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: AcbtcZhd1uUx1llkEdulngANk0QgEgAAegpK Thread-topic: cp -f option User-agent: Microsoft-Entourage/11.2.5.060620 on 10/11/06 1:12 PM, Jeffrey Ellis at jellis(a)dhnet.us wrote: > > on 10/11/06 6:32 AM, darwin-dev-request(a)lists.apple.com at > darwin-dev-request(a)lists.apple.com wrote: > >>> Sorry for being dense. Not sure I understand exactly what this does. Can >>> someone explain this...? >>> >>> -f For each existing destination pathname, remove it and create a new >>> file, without prompting for confirmation regardless of its >>> permissions. >>> >>> Doesn't cp do this by default unless you use -i or -n ...which this >>> overrides? >> >> No. >> >> $ cd /tmp >> $ cp /dev/null t >> $ chmod 600 t >> $ cp /dev/null t >> $ chmod 0 t >> $ cp /dev/null t >> cp: t: Permission denied >> $ cp -f /dev/null t >> $ >> >> -s > > Hi, Peter-- > > Sorry, but could you please explain this output step by step? I'm not sure I > really get what's happening... > > All My Best, > Jeffrey Hi, Peter-- Sorry, just went through this and it does seem perfectly understandable. Probably should have tried it before posting. My apologies <g> Thanks again :) All My Best, Jeffrey _______________________________________________ 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: cp -f option
by seebs＠plethora.net 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com In message <C1529E45.49CDE%jellis(a)dhnet.us>, Jeffrey Ellis writes: > >on 10/11/06 6:32 AM, darwin-dev-request(a)lists.apple.com at >darwin-dev-request(a)lists.apple.com wrote: > >>> Sorry for being dense. Not sure I understand exactly what this does. Can >>> someone explain this...? >>> >>> -f For each existing destination pathname, remove it and create a new >>> file, without prompting for confirmation regardless of its >>> permissions. >>> >>> Doesn't cp do this by default unless you use -i or -n ...which this >>> overrides? >> >> No. >> >> $ cd /tmp >> $ cp /dev/null t >> $ chmod 600 t >> $ cp /dev/null t >> $ chmod 0 t >> $ cp /dev/null t >> cp: t: Permission denied >> $ cp -f /dev/null t >> $ >> >> -s > >Hi, Peter-- > >Sorry, but could you please explain this output step by step? I'm not sure I >really get what's happening... 1. Create file called t. 2. Give self read/write privs on t. 3. Copy over t. It works, no problems. 4. Remove read/write privs on t. 5. Copy over t. Fails, permission denied. 6. Copy over, with -f, t. Succeeds. In short, that's what the -f flag does; it overrides permissions if it is able to do so. -s _______________________________________________ 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: cp -f option
by Jeffrey Ellis 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: AcbtcZhd1uUx1llkEdulngANk0QgEg== Thread-topic: cp -f option User-agent: Microsoft-Entourage/11.2.5.060620 on 10/11/06 6:32 AM, darwin-dev-request(a)lists.apple.com at darwin-dev-request(a)lists.apple.com wrote: >> Sorry for being dense. Not sure I understand exactly what this does. Can >> someone explain this...? >> >> -f For each existing destination pathname, remove it and create a new >> file, without prompting for confirmation regardless of its >> permissions. >> >> Doesn't cp do this by default unless you use -i or -n ...which this >> overrides? > > No. > > $ cd /tmp > $ cp /dev/null t > $ chmod 600 t > $ cp /dev/null t > $ chmod 0 t > $ cp /dev/null t > cp: t: Permission denied > $ cp -f /dev/null t > $ > > -s Hi, Peter-- Sorry, but could you please explain this output step by step? I'm not sure I really get what's happening... All My Best, Jeffrey _______________________________________________ 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: Embed Debug Break in Console App
by Eric Schlegel 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Oct 11, 2006, at 11:31 AM, Chris Edgington wrote: Debugger() does this: pthread_kill( pthread_self(), SIGINT ); I expect you could do the same. -eric _______________________________________________ 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… Sorry if this is documented somewhere - I've searched and cannot find it. How can I embed a debug break in an OSX console .c app that I'm debugging with gdb? I see in the "debugging magic" technote something about setting the USERBREAK environment variable and using SysBreak() or Debugger(). I tried including MacTypes.h - but I still get a link error for SysBreak() or Debugger(). So - my question is simple - how can I add a debug break in my console app? This email sent to site_archiver(a)lists.apple.com

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Re: Embed Debug Break in Console App
by Shantonu Sen 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com And by Carbon, you mean "-framework CoreServices" Shantonu On Oct 11, 2006, at 12:13 PM, Brian Bergstrand wrote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Oct 11, 2006, at 1:31 PM, Chris Edgington wrote: Thanks, -Chris This macro should do what you want w/o the need for Carbon: #ifdef __ppc__ #define trap() asm volatile("trap") #elif __i386__ #define trap() asm volatile("int $3") #else #error unknown arch #endif HTH. Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (Darwin) _______________________________________________ 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… Sorry if this is documented somewhere - I've searched and cannot find it. How can I embed a debug break in an OSX console .c app that I'm debugging with gdb? I see in the "debugging magic" technote something about setting the USERBREAK environment variable and using SysBreak() or Debugger(). I tried including MacTypes.h - but I still get a link error for SysBreak() or Debugger(). So - my question is simple - how can I add a debug break in my console app? You are getting a link error, because those are Carbon routines and you are probably not linking against the Carbon framework. iD8DBQFFLUJGedHYW7bHtqIRArJkAJ4wDgeZqU2dZe52kR6ky/i5oIjeSwCgvDcB A+RCHYOzxXhqtJHJdq1oxug= =MGxQ -----END PGP SIGNATURE----- _______________________________________________ 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/ssen %40opendarwin.org This email sent to ssen(a)opendarwin.org This email sent to site_archiver(a)lists.apple.com

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Re: Embed Debug Break in Console App
by Brian Bergstrand 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Oct 11, 2006, at 1:31 PM, Chris Edgington wrote: Thanks, -Chris This macro should do what you want w/o the need for Carbon: #ifdef __ppc__ #define trap() asm volatile("trap") #elif __i386__ #define trap() asm volatile("int $3") #else #error unknown arch #endif HTH. Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (Darwin) iD8DBQFFLUJGedHYW7bHtqIRArJkAJ4wDgeZqU2dZe52kR6ky/i5oIjeSwCgvDcB A+RCHYOzxXhqtJHJdq1oxug= =MGxQ -----END PGP SIGNATURE----- _______________________________________________ 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… Sorry if this is documented somewhere - I've searched and cannot find it. How can I embed a debug break in an OSX console .c app that I'm debugging with gdb? I see in the "debugging magic" technote something about setting the USERBREAK environment variable and using SysBreak() or Debugger(). I tried including MacTypes.h - but I still get a link error for SysBreak() or Debugger(). So - my question is simple - how can I add a debug break in my console app? You are getting a link error, because those are Carbon routines and you are probably not linking against the Carbon framework. This email sent to site_archiver(a)lists.apple.com

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Embed Debug Break in Console App
by Chris Edgington 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thanks, -Chris _______________________________________________ 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… Sorry if this is documented somewhere - I've searched and cannot find it. How can I embed a debug break in an OSX console .c app that I'm debugging with gdb? I see in the "debugging magic" technote something about setting the USERBREAK environment variable and using SysBreak() or Debugger(). I tried including MacTypes.h - but I still get a link error for SysBreak() or Debugger(). So - my question is simple - how can I add a debug break in my console app? This email sent to site_archiver(a)lists.apple.com

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question on defaults and LoginHook
by Philip Lukidis 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: AcbtSPp4sSTeoVtsR9i7FNxUgHg4YA== Thread-topic: question on defaults and LoginHook Hello, concerning LoginHook and defaults, I'm not clear if multiple scripts can be made to run upon login. Or is LoginHook restricted to a single login script? thanks, Philip Lukidis _______________________________________________ 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: MacOS X equivalent of swapon/swapoff?
by Steve Sisak 11 Oct '06

11 Oct '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -Steve _______________________________________________ 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… At 2:58 PM +0200 10/11/06, Jonas Maebe wrote: On 11 okt 2006, at 14:52, Steve Sisak wrote: It's somewhat annoying to need 4GB free on the root volume in order to burn a DVD. This is no longer needed as of Mac OS X 10.4 Point taken, but I was using that as a particularly egregious example of a general problem -- there's plenty of random unix code that will use gobs of space on /tmp (CUPS comes to mind). The general case is being able to specify a scratch (as opposed to swap) volume would be useful -- this need not be a dedicated partition: on my laptop it would be the big data partition. The ideas is to set things up so that "dumb" applications use the right location by redirecting common well known directories there (VM swap, /tmp, /Library/Caches, etc.) Doing this correctly is slightly tricky (especially on a running system), so it would best be handled by the system as a supported facility. This email sent to site_archiver(a)lists.apple.com

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