Guard's Blog

$ sudo su postgres -c '/opt/local/lib/postgresql91/bin/initdb -D /opt/local/var/db/postgresql91/defaultdb'
shell-init: error retrieving current directory: getcwd: cannot access parent directories: Permission denied
could not identify current directory: Permission denied
could not identify current directory: Permission denied
could not identify current directory: Permission denied
The program "postgres" is needed by initdb but was not found in the
same directory as "initdb".
Check your installation.

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$ sudo su postgres -c '/opt/local/lib/postgresql91/bin/initdb -D /opt/local/var/db/postgresql91/defaultdb'
shell-init: error retrieving current directory: getcwd: cannot access parent directories: Permission denied
could not identify current directory: Permission denied
could not identify current directory: Permission denied
could not identify current directory: Permission denied
The program "postgres" is needed by initdb but was not found in the
same directory as "initdb".
Check your installation.

Then first do

cd /opt/local/var/db/postgresql91/

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cd /opt/local/var/db/postgresql91/

I’m calling a function accepting a hash of options.

THe function is declared in a separate file included through script.

IDE highlights the keys that are not used in the function being called.

And also SO: Specify type of globals declared in another file.

A much-requested on SO function for sorting DOM elements.

jQuery.fn.sortItems = function (key) {
    var $items = [],
        $wrap = $('<div/>'),
        i, l;
    this.each(function () {
        $items.push([key(this), $(this)]);
    });
    if (!$items) {
        return;
    }
    $wrap.insertBefore($items[0][1]);
    $items.sort();
    for (l = $items.length, i = l - 1; i >= 0; i--) {
        $items[i][1].insertAfter($wrap);
    }
    $wrap.remove();
};

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jQuery.fn.sortItems = function (key) {
    var $items = [],
        $wrap = $('<div/>'),
        i, l;
    this.each(function () {
        $items.push([key(this), $(this)]);
    });
    if (!$items) {
        return;
    }
    $wrap.insertBefore($items[0][1]);
    $items.sort();
    for (l = $items.length, i = l - 1; i >= 0; i--) {
        $items[i][1].insertAfter($wrap);
    }
    $wrap.remove();
};

Demo.

Installed it on my home server under Ubuntu Server 11.04, configured daemon and web UI startup – looks really cool, as a normal full-featured desktop client

For 2 days I was burning various Windows PE / FreeDOS / custom tools to the RW trying to erase the BIOS setup password
Then just followed the official guide, released the keyboard in 5 minutes, and unplugged the RTC battery for extra 5 minutes — done.

Tiered of installing from sources?
The answer is as easy as

sudo port install py27-pyqt4

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sudo port install py27-pyqt4

Of course, the python version can be different for you.

This is good, popular and recommended to wrap every JS file in an anonymous closure function:

(function (){                                                         // (a)
    var module_wide_var = 0;                                          // (1)

    function inc() { module_wide_var += 1; return module_wide_var; }  // (2)
    function dec() { module_wide_var -= 1; return module_wide_var; }

    window.inc = inc;                                                 // (3)
    window.dec = dec;
}())                                                                  // (b)

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(function (){                                                         // (a)
    var module_wide_var = 0;                                          // (1)

    function inc() { module_wide_var += 1; return module_wide_var; }  // (2)
    function dec() { module_wide_var -= 1; return module_wide_var; }

    window.inc = inc;                                                 // (3)
    window.dec = dec;
}())                                                                  // (b)

Here we:

• (1) define a “global” variable,
• (2) define a couple of functions
• (3) expose our functions through the true global window object,

and everything is wrapped in an anonymous function (a), that’s instantly executed (b).

This approach implements the module pattern (well, in this case not clearly).

The whole function definition and invocation statement is wrapped in parens, because otherwise browsers fail to handle it as function expression.

There’s also 2 possible syntax for invocation – you can put it like (function (){ ... })() or (function (){ ... }()). I prefer the latter as recommended by Crockford (check for yourself).

OK, then, finally, a tiny point we forgot here: the trailing semicolon is the must.
The script above would work without any questions, until you try concateneting two of the kind. And for any big ptoject you’ll most probably have scripts compression and combining.

So, let’s see what happens:

(function (){ /* file 1 */ }())
(function (){ /* file 2 */ }())

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(function (){ /* file 1 */ }())
(function (){ /* file 2 */ }())

The 1st line is result of compressing the 1st file, the 2nd line, accordingly, represents the 2nd file. Now, see: the 2nd line is wrapped in parens (and it has to be), and from the JS point of view it immediately follows the 1st line, i.e. the code is equivalent to

(function (){ /* file 1 */ }())(function (){ /* file 2 */ }())

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(function (){ /* file 1 */ }())(function (){ /* file 2 */ }())

There’s no automatic semicolon insertion here.

This snippet is interpreted as function application, where the 1st part ((function (){ /* file 1 */ }())) is expected to return the function (we know, it returns undefined indeed), then parens follow, and inside them there’s function (){ /* file 2 */ }() that’s interpreted as the function argument.

What’s the problem? Well, the 1st part doesn’t return function, and the whole expression fails. With semicolons it would look like

(function (){ /* file 1 */ }());
(function (){ /* file 2 */ }());

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(function (){ /* file 1 */ }());
(function (){ /* file 2 */ }());

which clearly represents 2 separate expressions.

Even if you’re a good boy, you can be punished because of other’s lazyness

I always use anonymous closure for my scripts, and I always put the trailing semicolon. But because of other developer’s lazyness I encountered this error and was relly frustrated until I realized what happened.

Our project included the already minimized code of one jQuery plugin. For some reason (I’m not really interested) this code looked like

/* copyright and license comment */
eval(function(p,a,c,k,e,r){...})

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/* copyright and license comment */
eval(function(p,a,c,k,e,r){...})

This script was compressed with packer, and packer doesn’t care about anything that can follow its results – no semicolon there.

So, followed by my anon-closure-wrapped code, the 2 files combined were interpreted as a function execution, which, of course, failed.