随机取文件若干行

get_line_random.php

<?php

$file_name = "7";
$out = $file_name.".out";
$num = 3000;
$lines = get_lines_random( $file_name, $num);

foreach($lines as $key=>$value) {
    file_put_contents($out, $value, FILE_APPEND);
    file_put_contents($out, "\n", FILE_APPEND);
}

function get_lines_random( $filename, $lines_num ) {
    if( !file_exists($filename) ){
        return false;
    }

    $ret = array();
    $__tmp_ret= array();
    $data = file($filename); //将文件存放在一个数组中;
    $num = count($data); //条数;

    for ( $i=0; $i < $lines_num; $i++ ) {
        $id = mt_rand(0, $num-1); //随机数字;

        if( !in_array($id, $__tmp_ret) ) {
            array_push($__tmp_ret, $id);
            $text = chop($data[$id]); //显示第几行数据,并去除空格;
            $ret[$id] = $text;

        } else {
            $i--;
        }
    }
    return $ret;
}

?>