Category: PHP

PHP

Pen Drive Content Copier with PHP: The Source Code

Post author By masnun
Post date November 17, 2009
3 Comments on Pen Drive Content Copier with PHP: The Source Code

Nothing much to say. I am writing a PHP program that is intended to monitor for the availability of a directory and copy all data of that directory into another directory. It still needs huge improvements, testing and bug fixing. It was really fun coding it! 😀

Feel free to play with the codes and drop me a few lines if you have something to say ! 😀

Here’s the source code:

<?php

/*
 * Pen Drive Content Copier
 *
 * @Author Abu Ashraf Masnun
 * @Email  masnun@gmail.com
 * @URL    https://masnun.com
 *
 * @Description This script monitors for the availability of the
 * $source directory from time to time and copies all data into the
 * $target directory.
 *
 * //TODO Needs further improvements. Still in test phase. :(
 *
 */



$source = "/media/MASNUN"; // Source Directory -- Variable on Linux :-(
$target = "/home/masnun/copies"; // Target Directory
$sep = "/" ; // Directory Seperator


while(true) {
    scanMedia();
}

function scanMedia() {
    global $source, $target, $sep;

    if(is_dir($source)) {
        if(!file_exists($source.$sep."m17l40")) {
            full_copy( $source, $target );
            file_put_contents($source.$sep."m17l40","bWFzbnVuICYgbGFib255");
        }
    }

}



function full_copy( $source, $target ) {
    global $sep;
    if ( is_dir( $source ) ) {
        @mkdir( $target );
        $d = dir( $source );
        while ( FALSE !== ( $entry = $d->read() ) ) {
            if ( $entry == '.' || $entry == '..' ) {
                continue;
            }
            $Entry = $source . $sep . $entry;
            if ( is_dir( $Entry ) ) {
                full_copy( $Entry, $target . $sep . $entry );
                continue;
            }
            copy( $Entry, $target . $sep . $entry );
        }

        $d->close();
    }else {
        copy( $source, $target );
    }
}


if(!function_exists("file_put_contents")) {

    function file_put_contents($source,$data) {
        $fh = fopen($source,"w");
        return fwrite($fh,$data);

    }


}

?>

<?php

* Pen Drive Content Copier

* @Author Abu Ashraf Masnun

* @Email masnun@gmail.com

* @URL https://masnun.com

* @Description This script monitors for the availability of the

* $source directory from time to time and copies all data into the

* $target directory.

* //TODO Needs further improvements. Still in test phase. :(

$source = "/media/MASNUN"; // Source Directory -- Variable on Linux :-(

$target = "/home/masnun/copies"; // Target Directory

$sep = "/" ; // Directory Seperator

while(true) {

scanMedia();

}

function scanMedia() {

global $source, $target, $sep;

if(is_dir($source)) {

if(!file_exists($source.$sep."m17l40")) {

full_copy( $source, $target );

file_put_contents($source.$sep."m17l40","bWFzbnVuICYgbGFib255");

}

function full_copy( $source, $target ) {

global $sep;

if ( is_dir( $source ) ) {

@mkdir( $target );

$d = dir( $source );

while ( FALSE !== ( $entry = $d->read() ) ) {

if ( $entry == '.' || $entry == '..' ) {

continue;

}

$Entry = $source . $sep . $entry;

if ( is_dir( $Entry ) ) {

full_copy( $Entry, $target . $sep . $entry );

continue;

}

copy( $Entry, $target . $sep . $entry );

}

$d->close();

}else {

copy( $source, $target );

}

if(!function_exists("file_put_contents")) {

function file_put_contents($source,$data) {

$fh = fopen($source,"w");

return fwrite($fh,$data);

}

PHP

Calling system() on PHP

PHP is no longer just a scripting language for web automation. It has grown very rapidly and now holds the position of the 3rd most popular programming language worldwide. PHP is now being widely used for CLI programs and even GUIs 😀

While working on a daemon script at Leevio, I was executing a shell script using the shell_exec() function. Rana vai pointed me to the system() function which is quite identical to it’s C equivalent. I was really glad to have found it at last. I was looking for a function that has interactive output like Python’s os.system() call. It was in PHP from PHP4 and I never looked into it! 🙁 Shame on me!

The system() function takes a command, executes it, prints out all the outputs of the command and returns the last line of the output. We can additionally pass a variable as the optional second parameter that will hold the entire return value.

<?php
$last_line = system('ls', $retval);
echo "{$last_line} \n {$retval} \n";
?>

<?php

$last_line = system('ls', $retval);

echo "{$last_line} \n {$retval} \n";

The “ls” command lists all the contents of a directory. The above php script is supposed to print out all the contents of the current working directory aka CWD 😀

PHP

Running a PHP Script as Daemon

Post author By masnun
Post date November 2, 2009
6 Comments on Running a PHP Script as Daemon

For our ongoing project at Leevio, I had to find a way to run a php script as a daemon. I checked out a few techniques. I didn’t like any of them much. I needed a way to run the intended script and then exit the terminal leaving the script to keep running in the background.

After a bit of hard work, I chose to use the PCNTL functions to achieve my goal. Here’s the code I used:

<?php
declare(ticks=1);

$pid = pcntl_fork();
if ($pid == -1) {
    die("could not fork");
} else if ($pid) {
        exit(); // it's the parent -- lets quit
    } else {
    // it's the child -- nothing to do at the moment
    }

// detatch from the terminal
if (posix_setsid() == -1) {
    die("could not detach from terminal");
}

// setup signal handlers
pcntl_signal(SIGTERM, "sig_handler");
pcntl_signal(SIGHUP, "sig_handler");

// launch the script -- transfer the args to the child script
shell_exec("php script.php {$argv[1]} {$argv[2]} {$argv[3]} ");

function sig_handler($signo) {

    switch ($signo) {
        case SIGTERM:
        // handle shutdown tasks
            exit;
            break;
        case SIGHUP:
        // handle restart tasks
            break;
        default:
    // handle all other signals
    }

}

?>

<?php

declare(ticks=1);

$pid = pcntl_fork();

if ($pid == -1) {

die("could not fork");

} else if ($pid) {

exit(); // it's the parent -- lets quit

} else {

// it's the child -- nothing to do at the moment

}

// detatch from the terminal

if (posix_setsid() == -1) {

die("could not detach from terminal");

}

// setup signal handlers

pcntl_signal(SIGTERM, "sig_handler");

pcntl_signal(SIGHUP, "sig_handler");

// launch the script -- transfer the args to the child script

shell_exec("php script.php {$argv[1]} {$argv[2]} {$argv[3]} ");

function sig_handler($signo) {

switch ($signo) {

case SIGTERM:

// handle shutdown tasks

exit;

break;

case SIGHUP:

// handle restart tasks

break;

default:

// handle all other signals

}

Note that, in this case, the daemon quits the moment the shell_exec() command is executed. We are executing our intended PHP script as a sub process which has been detached from the terminal. The script has a while loop to keep it running forever. So, we can safely quit the main process while the forked process remains alive with the php script being executed 😀

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