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stream_socket_client() fails with no errors...

Today I had a weird one.

The PHP function named stream_socket_client(), used to create a socket to communicate with another computer over a network, may return $errno = 0 and $errstr = "".

The PHP reference actually mentions the problem:

On failure the errno and errstr arguments will be populated with the actual system level error that occurred in the system-level connect() call. If the value returned in errno is 0 and the function returned FALSE, it is an indication that the error occurred before the connect() call. This is most likely due to a problem initializing the socket. ...

Setting the color of a cell in LibreOffice Calc depending on the cell value...

Introduction

This is not the first time I try to look into getting a color in a cell when the value of the cell is such and such, not just smaller than 0 and it becomes [RED]... which is a default available in your formula.

The fact is that you need to create styles that you're going to reference either with the STYLE() function or using the Conditional Formatting window.

So...

Creating New Styles and Formatting

First select a cell. You probably want to use an empty cell where you can enter a number or some text and then change it's format with the Format Cell... option. ...

Add or subtract to a Time field in LibreOffice

Today I was working on a spreadsheet where I added a time for a calendar type of sheet.

What I wanted to do is have a column where time increases without having to type each time manually.

So I needed to add 15 or 30 minutes to the first time.

Say my first time is 7am, it appears as 07:00:00 AM.

In the next row (B4), I wanted to do something like:

=B3+"15 minutes"

The fact is that LibreOffice saves time and date as a double number where 1.0 represents 1 day.

So to add just 15 minutes, you need to divide your number by the number of minutes in a day:

=B3+15/60/24

Or if ...

How do I force my viewport scale to 1.0?

I just spent hours trying to understand how the viewport functions. You can change it dynamically, but only once. That is. set it to a certain value and let the GUI take that new value in account. Then later you can change it again with another value, if you'd like.

What I was looking to do is reset the zoom back to 1.0 after a user clicked on an image and very likely zoomed in and out to better see the image. At the time the user is done, he clicks the image once and it comes back to the website. Only, the zoom remains the same by default. Which somewhat makes sense since the browser ...

Can I create an INDEX to accelerate a SELECT MIN(IF(...)) in MySQL?

I have a table with a few columns, two of which are integers, one of which can be NULL in which case the other integer is to be used in my query.

CREATE TABLE my_table (col1 INTEGER NOT NULL, col2 INTEGER);

If `col2` is NULL, then use `col1`. As is, there is how my query looks like:

SELECT MIN(IF(col2, col2, col1)) AS smallest FROM my_table LIMIT 1;

In other words, I need to get the row with the smallest integer, but if one column is NULL, I want to use the other column value.

On a very small sample, the query is still very fast, but the real version is not unlikely to have thousands ...

Display a line number in a table (i.e. subform of records)

I was ask by a customer to add line numbers to each entry in a table shown in an invoice.

The concept is pretty simple, but really, how do you do that properly in MS-Access?

Microsoft actually has a solution (see link below) and it comes down to writing a function that counts the number of items from that item's current position to the beginning of the table (i.e. going backward). It works, it is just really bad if you have very large invoices since it will tend to slow down as you start getting many items.

There is the function, we can see the counting in the do until near the end ...

Large scale Linux console

As I am working on our Snap! C++ CMS, I created a set of virtual systems to test the compilation on "clean" system (yeah! my main computers has all sorts of things that I don't even know about...)

In those virtual system, I only install the basic server and then do a sudo apt-get install of anything else the server needs to get compiled. This includes libraries such as libmagic, boost, and Qt and some tools like xmllint. This is pretty cool, but when working in a console, and that console is very small, it makes it a bit difficult, so I looked into making it big.

For this ...

Debug and/or Release specific command line option in cmake

Today I ran in a problem with cmake which was to very simply select /MT instead of /MD for a small set of projects. The problem is that so far this feature was at least on a per directory basis. Since the exact same directory is used to build the dynamic (DLL) and static (.lib) libraries, having two directories is not exactly an option here.

set ( CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT" )
set ( CMAKE_C_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT" )
set ( CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_RELEASE} /MTd" )
set ( CMAKE_C_FLAGS_DEBUG ...

Setting up an array of JavaScript functions in jQuery

Today I worked a bit with jQuery to create an advanced form. Advanced just because it is tabbed and appears in a pop-up, nothing too major really. Maybe later I'll add some tests to validate the data being entered before someone can submit the form...

In any event, I ran in a problem which was to create a set of click callback functions (event handlers) and each of which should make use of a different index. So... I have 4 tabs and each one has a number: 1, 2, 3, and 4.

Say I call each one of these numbers #tab1, #tab2, #tab3, and #tab4. Now I want to create a click function on each one ...

get_defined_vars() PHP function

Once in a while, I need to get the complete list of all the variables available in a PHP piece of code.

This is done with the get_defined_vars() PHP function. It's very simple, it returns an array of name / value pairs. You can then print that value using print_r() or var_dump().

That's it!

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  • IsNull

    The Visual Basic function to check whether a value is set to Null. The PHP equivalent is is_null().

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    Unix command line tool used to list processes currently running. On some older Unices, it would also show zombies (processes that have exited but with parents who have not yet acknoledged their death.)

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