Asynchronously files upload with jQuery

Posted on February 27, 2013 by Alok Sah

Have you ever uploaded files with jquery without using any plugin.
If “NO”, then try to do it using Ajax request and Formdata objects.

Finally done it,after experiment.

To upload files please start with “html form ”


<form id="upload_form" enctype="multipart/form-data">
<input name="file_name" type="file" id="file_name"  />
<input type="button" value="Upload File" />
</form>

Initiate formData object and then appending file field to it using append() method it to file as:


var formData = new FormData();
formData.append( 'file', $( '#file_name' )[0].files[0]);

var FileUrl    = 'upload.php?action=uploadfile';
var uploadRes    = ajaxFileUpload(FileUrl,formData);

Now, to handle file , upload use ajax as function ajaxFileUpload as below :


function ajaxFileUpload(FileUrl,formData, request_timeout)
{
if(!request_timeout)
request_timeout = 50000;

$.ajax({
url: strFileUrl,  //server script to process data
type: 'POST',
timeout: request_timeout,
// Form data
data: formData,
//Options to tell JQuery not to process data or worry about content-type
cache: false,
contentType: false,
processData: false
});

}

Hope, you have got the solution !!

PHP Encoding with base64

Posted on October 9, 2012 by Alok Sah

Suppose you have a long file data and you have to save the same in the database. this data is too long and contains some especial character like (\, /, *…etc ) that can corrupt your database or can’t be inserted.
I was working on some configuration file and have to insert it in the database, but didn’t get success in inserting it as it is, because of special characters.

So let’s take “php.ini” configuration file to save this content on database, use php function base64_encode() which encodes data with MIME base64


// its too big file and and have lot of special character
$file = "php.ini";
$file_data	= file_get_contents("$file");
$encode_config_file = base64_encode(implode("\n", $file_data));

now above variable “$encode_config_file” can store this data into the database as a string.
and when we want to fetch and work with this data we need to decode with php function base64_decode()

below code show the fetching of data using base64_decode function:

// $file_data keep encoded string fetched from database
$file_decode = base64_decode($file_data);
echo $file_decode;

/// Output Some part of php.ini like:

// ; allow_call_time_pass_reference
// ;   Default Value: On
// ;   Development Value: Off
// ;   Production Value: Off

Happy Coding…:)

Linux command and PHP

Posted on April 18, 2012 by Alok Sah

In Operating systems either it is linux, unix or windows system, there are programs which are running on background to keep system functional, these programs are called processes. in linux or unix like systems we have ps command to view processes running on system.
ps command is used to check currently running process status on linux or unix systems. To execute this command just type ps and enter you will have all the currently running process.

$ ps
 PID  TT  STAT      TIME COMMAND
 1175  v0  Is+    0:00.00 /usr/local/man/ps
 1176  v1  Is+    0:00.00 /usr/bin/prox
 63552   0  R+     0:00.00 ps

If you have something wrong or problem from any process you can kill that process from knowing his process id and type command

 $ kill 1175
 $ kill 1175 1176 # for multiple killing process

All linux command has many options to display the description that we can view by man command.
Suppose we have to view the process for some specific user.

 $ man ps # display command description
 $ ps –auwx | grep xyz_user | grep php
 xyz_user  1302  0.0  1.0 60804 10140  ??  I     4Apr12   0:01.65 /usr/local/bin/php /usr/local/www/apache/phpCli.php
 xyz_user  7471  0.0  1.0 60804 10516  ??  I    Wed11AM   0:01.12 /usr/local/bin/php /usr/local/www/apache2/commxyz.php

Above ps command show how can we do pattern searching with the help of grep command, here we search all the currently running process for specific user and having matched string ‘php’ . In result we get PHP files for that specific user running on system along with process id, time and path of that file.

Let’s try now second command to view process, top: its show all running top process like in windows we watch process in “Task manager” process. Simple we can get this by top in linux.

 $ top
 last pid: 72169;  load averages:  0.00,  0.01,  0.00 up 12+22:19:36  10:29:31
 59 processes:  1 running, 58 sleeping
 CPU:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
 Mem: 114M Active, 524M Inact, 216M Wired, 41M Cache, 111M Buf, 56M Free
 Swap: 2011M Total, 220K Used, 2011M Free
 PID USERNAME       THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU COMMAND
 70726 www              1  45    0   131M 18188K select  1   0:02  0.29% httpd
 1025 pgsql            1  44    0 23820K  4444K select  0   2:11  0.00% postgres
 1022 pgsql            1  44    0 64132K 16032K select  1   1:17  0.00% postgres
 1053 root             1  44    0   129M 12848K select  1   0:26  0.00% httpd

This top command result so many information like last processed id, load average of system, uptime, CPU States, memory and swap. If you watch out the screen, you must view the processes running currently and all his information as PID, username time CPU usage etc.

Now if you want these commands to run from php script, there are many php inbuilt function to execute linux commands like exec, system, passthru, shell_exec , backtick operator (` `) etc. we can try any of these to execute linux command by php.
Suppose we have to execute above process command by command line script

 // create a variable
 $ps_cmd = "ps -auwx | grep xyz_user| grep php";
 // execute by backtick operator
 $ps_exec = `$ps_cmd`;
 // output
 var_dump($ps_exec);
 OR
 $psexc = exec($ps_cmd, $ps_output, $ps_result);
 var_dump($ps_output);
 var_dump($ps_result);

This will output as same above all the currently running process for specific user and having matched string ‘php’. In case of using backtick operator we get above result. Using exec we get output in two parameter: output and result. output gives an array and result give either command executes successfully or not.

Quick Review on SQLite with PHP

Posted on January 8, 2012 by Alok Sah

Searching for a minimal size of database i found SQLITE the best. one simple file that not take more space (in KB) and supports multiple table, index view, triggers and many more, all data is stored in one single file and work as a database engine.
Working with php, i use Sqlite3 version.

To execute a sqlite statement webserver should have a full permission to this directory and database file.
Suppose we have a sqlite database file name sqlitedb.s3db (extension is s3db). first let start with creation a database.

Creating a Connection and Database

// creating a connection with database
$dbConnSqlite = new SQLite3("sqlitedb.s3db");
// database creation
$sqlCreateTable="Create table person(
 id INTEGER PRIMARY KEY NOT NULL,
 name text,
 age  INTEGER
 )";
if($dbConnSqlite->query($sqlCreateTable))
{
 $sqlInsert = “Insert into person values(‘xyz’,2)”;
 $dbConnSqlite->query($sqlInsert));
}

Above example open a SQLite3 database “sqlitedb” connection, create a table “person” and insert one row to database.
Sqlite is not rich in datatype but have some common datatype integer, varchar, text, which fullfil our requirement. In this example i am using query() to execute sql statment.

Fetching Data

$sqlPerson= "select * from person";
if($resSql = $dbConnSqlite->query($sqlPerson))
{
 while($rowSql = $resSql->fetchArray(SQLITE3_ASSOC))
 {
 echo "Person name is: " . $rowSql['name'] . "and his age is" . $rowSql['age'] . "\n";
 }
}
else
{
 Echo "Query Failed";
}

In above example call fetchArray to read data from database with passing “SQLITE3_ASSOC” flag.

In Sqlite libraries flags are of three type:
1> SQLITE_ASSOC: fetch associative array
2> SQLITE_NUM: fetch index array
3> SQLITE_BOTH :fetch assoctive array with index

Function to get Number of Rows in table and last insert id

// $numRows give number of rows
$numRows = sqlite3_num_rows($sqlPerson);

// This function return number of rows
public function sqlite3_num_rows($query, $flag="both")
{
 global $dbConnSqlite;
 $result = $dbConnSqlite->query($query);
 if(!$result) //make sure the result is valid
 return NULL;

 if($flag=="assoc")
 $flag = SQLITE3_ASSOC;
 else if($flag=="num")
 $flag = SQLITE3_NUM;
 else
 $flag = SQLITE3_BOTH;
 $numArray = array();
 $i = 0;
 while($res = $result->fetchArray($flag))
 {
 $numArray[$i] = $res;
 $i++;
 }
 $numRows = count($numArray);
 return $numRows;
}

// To get last insert id
$sqlInsert = “Insert into person values(‘johny’,22)”;

if(!$dbConnSqlite->query($sqlInsert))
{
 echo "Query failed.";
 }
else
{
 $insertId = "SELECT last_insert_rowid() AS insert_id";
 $result        = $dbConnSqlite->query($insertId);
 // Call to function
 $numRows    = sqlite3_num_rows($insertId, "num");
 if($numRows > 0)
 {
 $rows = $result->fetchArray(SQLITE3_ASSOC);
 $insert_id    = $rows['insert_id'];
 }
}

First off, we have simple function that return number of rows in table. now to get last insert id in sqlite it has select statment “SELECT last_insert_rowid() AS insert_id”.

In Sqlite we also have unique key, foreign key constraints and can create trigger too as we create similar in other databases. this article is a way to start experimenting a simple file that give you a big result.

References: www.sqlite.org

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Asynchronously files upload with jQuery

PHP Encoding with base64

Linux command and PHP

Quick Review on SQLite with PHP

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