<?php
use Archive7z\Archive7z;

$obj = new Archive7z('path_to_7z_file.7z');

foreach ($obj->getEntries() as $entry) {
        print_r($entry);
        /*
Archive7z\Entry Object
(
    [path:Archive7z\Entry:private] => test/test.txt
    [size:Archive7z\Entry:private] => 14
    [packedSize:Archive7z\Entry:private] => 19
    [modified:Archive7z\Entry:private] => 2013-10-23 16:28:51
    [attributes:Archive7z\Entry:private] => A
    [crc:Archive7z\Entry:private] => A346C3A7
    [encrypted:Archive7z\Entry:private] => -
    [method:Archive7z\Entry:private] => LZMA:16
    [block:Archive7z\Entry:private] => 2
    [archive:Archive7z\Entry:private] => Archive7z\Archive7z Object
        (
            [compressionLevel:protected] => 9
            [cliLinux:protected] => /usr/bin/7za
            [cliBsd:protected] => /usr/local/bin/7za
            [cliWindows:protected] => C:\Program Files\7-Zip\7z.exe
            [cli:Archive7z\Archive7z:private] => C:\Program Files\7-Zip\7z.exe
            [filename:Archive7z\Archive7z:private] => path_to_7z_file.7z
            [password:Archive7z\Archive7z:private] => 
            [outputDirectory:Archive7z\Archive7z:private] => ./
            [overwriteMode:Archive7z\Archive7z:private] => -aoa
            [changeSystemLocale:protected] => 
            [systemLocaleNix:protected] => en_US.utf8
            [systemLocaleWin:protected] => 65001
        )

)
         */

    if ($entry->getPath() === 'test/test.txt') {
        $entry->extractTo('path_to_extract_folder/'); // extract file
    }
}

echo $obj->getContent('test/test.txt');

$obj->setOutputDirectory('path_to_extract_folder/');
$obj->extract(); // extract archive

$obj->addEntry(__FILE__); // add file to archive
$obj->addEntry(__DIR__, true);  // add directory to archive (include subfolders)