#ifdef __APPLE__
void log_and_exec_reboot_or_halt(void);
#else
void die_you_gravy_sucking_pig_dog(void);
#endif

Sure, it does the same thing, but I don’t think log_and_exec_reboot_or_halt has the same panache.

<dict>
	<key>allow-root</key>
	<false/>
	<key>class</key>
	<string>rule</string>
	<key>comment</key>
	<string>For use by Apple.  WARNING: administrators are advised not to
	        modify this right.</string>
	<key>k-of-n</key>
	<integer>1</integer>
	<key>rule</key>
	<array>
		<string>is-admin</string>
		<string>is-developer</string>
		<string>authenticate-developer</string>
	</array>
	<key>shared</key>
	<true/>
</dict>

The upshot of this is that if you aren’t in the _developer group in the local directory, you’ll have to authenticate as an administrator to use gdb or some of the performance tools. For the vast majority of developers on Mac OS X, who run as an administrator, this is fine, but if you’re running as a regular user, either for security reasons or because you’re in something like a lab setting, this can be a problem. To add a user to the _developer group, use the dscl command:

dscl . -append /Groups/_developer GroupMembership UserName

Replace UserName with the short name of your user account (or $(whoami)) and you should be all set.

If you’re administering Mac OS X in a lab setting, you can either create a LaunchAgent that handles this or a login hook. See the Apple tech note “Running At Login” for more information on login hooks. As an added touch, my login and logout scripts to handle this also remove all users from the group, like so:

dscl . -delete /Groups/_developer GroupMembership

If the GroupMembership key doesn’t exist, dscl will create it—and it doesn’t exist by default—so deleting it outright shouldn’t cause any problems.

$ svn add Icon\@2x~iphone.png
svn: warning: 'Icon' not found

The fix, thanks to the subversion_users Google Group, is to add another @ to the end of the filename, like so:

$ svn add ./Icon\@2x~iphone.png@
A  (bin)  Icon@2x~iphone.png

If you’d like to do this for all of your high-resolution art in a folder, here’s a tiny Bash command for the task:

for x in `ls *\@*`; do svn add $x\@; done

##
# Determine if the network is up by looking for any non-loopback
# internet network interfaces.
##
CheckForNetwork()
{
	local test

	if [ -z "${NETWORKUP:=}" ]; then
		test=$(ifconfig -a inet 2>/dev/null | sed -n -e '/127.0.0.1/d' -e '/0.0.0.0/d' -e '/inet/p' | wc -l)
		if [ "${test}" -gt 0 ]; then
			NETWORKUP="-YES-"
		else
			NETWORKUP="-NO-"
		fi
	fi
}

In your code, simply include rc.common, then call CheckForNetwork as needed. An example:

#!/bin/bash

# Example Daemon Starter
. /etc/rc.common

CheckForNetwork

while [ "${NETWORKUP}" != "-YES-" ]
do
        sleep 5
        NETWORKUP=
        CheckForNetwork
done

# Now do what you need to do.

Note that this will keep the script running indefinitely until CheckForNetwork sets NETWORKUP to “-YES-,” so if there’s a networking problem your code may never execute.

current cache invalid because /System/Library/Frameworks/WebKit.framework/Versions/A/WebKit has changed

Running the update_dyld_shared_cache command will fix this, but there’s a better way. Sure, there’s almost no overhead to that command, but where’s the fun in that? Here’s a pre-apply script that will delete any shared caches that have changed, which will then be re-built at reboot.

#!/bin/sh

# update_dyld_caches: Inspects the applicable transcript for something that
#                     might cause a dyld cache to become outdated. If it exists,
#                     delete the cache so it's re-created at startup.

DYLD_CACHE_FOLDER="/private/var/db/dyld"
DYLD_PREFIX="dyld_shared_cache_"
ARCHITECTURES="i386 x86_64 rosetta ppc ppc64"

for arch in ${ARCHITECTURES}; do
	cache="${DYLD_CACHE_FOLDER}/${DYLD_PREFIX}${arch}"
	map="${DYLD_CACHE_FOLDER}/${DYLD_PREFIX}${arch}.map"

	if /bin/test -f "${cache}"; then
		if /bin/test -f "${map}"; then
			/bin/cat "${map}" | grep ^/ | sort --unique --ignore-case | while read line; do
				if /bin/test -n "$(grep ${line} ${1})"; then # found a match
					/bin/rm -f "${cache}"
					/bin/rm -f "${map}"
					break;
				fi
			done
		else
			# Cache exists, but there's no map.
			/bin/rm -f "${cache}"
		fi
	fi
done

/private/var/radmind/preapply/update_kernel_extensions:

#!/bin/sh

# update_kernel_extensions: Manage the replacement of old kernel extensions.
#                           If there are updates, kill kextd and destroy the
#                           caches.

KEXT_CACHE="/System/Library/Caches/com.apple.kext.caches"
KEXT_FOLDER="/System/Library/Extensions"
KEXTD_LAUNCHD="com.apple.kextd"
SYSTEM_LAUNCHD_FOLDER="/System/Library/LaunchDaemons"

transcript="${1}"
result="${transcript}.$$"

/usr/bin/grep "${KEXT_FOLDER}" "${transcript}" > "${result}"

if test -n "${result}"; then #result is non-empty
    # Disable kextd to prevent it from recreating kernel extension caches, which
    # will be re-created at startup.
    if test -n "$(/bin/launchctl list | /usr/bin/grep ${KEXTD_LAUNCHD})"; then
        #kextd is running
        /bin/launchctl unload "${SYSTEM_LAUNCHD_FOLDER}/${KEXTD_LAUNCHD}.plist"
    fi

    # Remove kernel extension cache.
    /bin/rm -rf "${KEXT_CACHE}"
fi

rm -f "${result}"

In its present form, it only works on Snow Leopard, but I’ll be updating it to work on Leopard as well.

using terms from application "iChat"
	tell application "iChat"
		activate
		log in
		delay 5
		set theBuddy to buddy "ScreennameGoesHere" of service "AIM"
		try
			set theStatus to status of theBuddy
		on error errmesg number errno
			set message to display dialog "The user is currently unavailable." buttons {"OK"}
			quit
			return
		end try
		if theStatus is available then
			set theCapabilities to get capabilities of theBuddy
			if (theCapabilities contains multiperson video) then
				send "A user is attempting to contact you." to theBuddy
				delay 2
				tell service "AIM" to make video chat with properties {participants:theBuddy}
				set theChat to result
				delay 30
				try
					set theStatus to the av connection status of theChat
				on error errmesg number errno
					quit
					return
				end try
				repeat while theStatus is not ended
					delay 5
					try
						set theStatus to the av connection status of theChat
					on error errmesg number errno
						quit
						return
					end try
				end repeat
				quit
				return
			else
				set message to display dialog "The user cannot video chat at this time. Please try again later." buttons {"OK"}
				quit
				return
			end if
		else
			set message to display dialog "The user is currently unavailable." buttons {"OK"}
			quit
			return
		end if
	end tell
end using terms from

A couple of gotchas:

• I tried using video chat instead of multiperson video, but that always returned false. I don’t know why.
• Once the video chat has ended, you can’t poll its status (hence the try block).

Thank you for submitting your application to the App Store. Unfortunately, your application, uWarranty, cannot be added to the App Store because it violates section 3.3.7 of the iPhone Developer Program License Agreement:

“Applications may not perform any functions or link to any content or use any robot, spider, site search or other retrieval application or device to scrape, retrieve or index services provided by Apple or its licensors, or to collect, disseminate or use information about users for any unauthorized purpose.”

OK, I get it. That’s fine and is Apple’s prerogative. But now I have this program and all the development time that went into it. So what do I do? I guess the answer is to open-source it, just like AppSales Mobile. Watch this space for more details as I clean up the code and throw it up on a public repository somewhere.

This should all happen in the - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string method of your UITextField’s delegate (which, of course, must implement the UITextFieldDelegate protocol). I’ve implemented it as follows:

- ( BOOL )textField:( UITextField * )textField
shouldChangeCharactersInRange:( NSRange )range
  replacementString:( NSString * )string
{
    /*
     * We only want uppercase letters and numbers in this text field, so if
     * this method is adding something else, we don't want it. But we also
     * want to support copy-and-paste, so it's not always going to be one
     * character added.
     */
    BOOL shouldAllowChange = YES;

The shouldAllowChange variable is set to YES initially because we want to allow this change when possible. The method will test the string to see if it meets criteria for rejection as we move forward.

    NSMutableString *newReplacement =
    [[ NSMutableString alloc ] initWithString:[ string uppercaseString ]];

    if ( ! [ string isEqualToString:newReplacement ]) {
        shouldAllowChange = NO;
    }

First, we define newReplacement. It’s an NSMutableString so that if we discover non-alphanumeric characters in it, we can remove them on-the-fly. It also serves as a convenient string against which we can test to see if string is already uppercase.

    NSCharacterSet *desiredCharacters =
    [ NSCharacterSet alphanumericCharacterSet ];

    for ( NSUInteger i = 0; i < [ newReplacement length ]; i++ ) {
        unichar currentCharacter = [ newReplacement characterAtIndex:i ];

        if ( ! [ desiredCharacters characterIsMember:currentCharacter ]) {
            shouldAllowChange = NO;
            [ newReplacement deleteCharactersInRange:NSMakeRange( i, 1 )];
            i--;
        }
    }

In this section, we define the NSCharacterSet that we want to work with - in this case, the alphanumeric character set. We go through one character by a time and if the current character isn’t alphanumeric, we remove it from the NSMutableString (decrementing i so that we don’t inadvertently skip a character) and set our shouldAllowChange flag accordingly.

    if ( shouldAllowChange ) {
        [ newReplacement release ];
        return YES;
    } else {
        [ textField setText:[[ textField text ]
                             stringByReplacingCharactersInRange:range
                             withString:newReplacement ]];
        [ newReplacement release ];
        return NO;
    }
}

To finish, if shouldAllowChange is still true, we return YES and allow the replacement characters to be added. Otherwise, we return NO, but not before using our replacement replacement string (say that ten times fast) to manually edit the text field’s text. The end result is a text field that will consist only of uppercase letters and numbers.

• /usr/include/netinet/ip.h
• /usr/include/netinet/in_systm.h
• /usr/include/netinet/ip_icmp.h
• /usr/include/netinet/ip_var.h

So here’s a quick Bash script that links the relevant files to your iPhone OS and iPhone Simulator SDKs:

for path in /Developer/Platforms/iPhone*/Developer/SDKs/*; do
    for file in /usr/include/netinet/ip.h \
                /usr/include/netinet/in_systm.h \
                /usr/include/netinet/ip_icmp.h \
                /usr/include/netinet/ip_var.h; do
        if [ ! -f "${path}${file}" ]; then
            sudo ln "${file}" "${path}${file}"
        fi;
    done;
done

I’ve spoken to an Apple engineer and confirmed that this is the best way to do it, as well as filed a bug, which I encourage you to do as well if this annoys you.