Martello

I’ve had reason to capture rather a lot of screen shots in recent weeks and find the following Mac keyboard shortcuts very useful:

There are lots of other variations on the above, which are described nicely  here.

This one’s been bugging me for several weeks so finally got around to finding a proper solution. Basically, if someone sends you a PDF file with some photos in it, the chances are they didn’t think of reducing the picture quality (in the original document) before creating the PDF. As a result, the PDF file can end up being enormous, for no obvious reason to the reader.

While I managed to find out how to tackle the problem from inside the likes of Microsoft Word (better options in Office 2011), I am often without the original document, so what to do there (on a Mac)?

Well, as it happens, Mac Preview does have a way of doing this which I found out about here, and while it worked well for me (PDF files were mostly text with 2-3 pictures anyway), I have seen comments on the above article questioning the quality of the resulting file. Still, it may work for you too.

Had some strange behaviour with DNS on Mac OS X earlier today. Made a change inside DNS and waited the required amount of time for the TTLs to expire. Then verified that the new IP address was resolving (using both dig and nslookup).

However, my system was still trying to use the old IP address when I tried a simple ssh or telnet command.

In the end, I discovered how to flush my local DNS cache, which fixed the problem. You can do this as follows:

$ dscacheutil -flushcache

Here is a useful MySQL command that shows (an approximation of) the amount of storage (disk and memory) consumed by each table in a MySQL database.

SELECT
 TABLE_NAME,
 TABLE_ROWS,
 DATA_LENGTH / (1024*1024),
 INDEX_LENGTH / (1024*1024),
 (DATA_LENGTH + INDEX_LENGTH) / (1024*1024) as total
FROM
 information_schema.TABLES
WHERE
 TABLE_SCHEMA = (SELECT DATABASE())
GROUP BY
 TABLE_NAME
ORDER BY
 total;

Please bear in mind that the data returned will be an approximation, but should still show you a reasonable enough split which of your tables are consuming most of the resources.

Like most email clients, Mozilla Thunderbird has a very useful auto-complete function which allows you to choose from previously-used email addresses when composing a new message. However, removing entries from this list is not as easy (or obvious)  in Thunderbird as it is in Microsoft Outlook, for example, where all you have to do is press the DEL key when the auto-complete list pops up.

Instead, Thunderbird seems to store the auto-completion list in a section of the Address Book called Collected Addresses. To remove an entry you have to:

1. Click the large Address Book button in the main (Mail Filter) toolbar
2. Select the Collected Addresses group
3. Locate and delete the desired addresses from there

Source: mozillaZine Forums