腾讯PHP工程师笔试题

1． 请对POSIX风格和兼容Perl风格两种正则表达式的主要函数进行类比说明
ereg preg_match
ereg_replace preg_replace

2． 请说明在php.ini中safe_mode开启之后对于PHP系统函数的影响

3． PHP5中魔术方法函数有哪几个，请举例说明各自的用法

__sleep
__wakeup
__toString
__set_state
__construct,
__destruct
__call,
__get,
__set,
__isset,
__unset
__sleep,
__wakeup,
__toString,
__set_state,
__clone
__autoload

4． 请写出让，并说明如何在命令行下运行PHP脚本（写出两种方式）同时向PHP脚本传递参数？

5． PHP的垃圾收集机制是怎样的

6．使对象可以像数组一样进行foreach循环，要求属性必须是私有。
(Iterator模式的PHP5实现，写一类实现Iterator接口)

7．请写一段PHP代码，确保多个进程同时写入同一个文件成功

8． 用PHP实现一个双向队列

9． 使用正则表达式提取一段标识语言（html或xml）代码段中指定标签的指定属性值（需考虑属性值对不规则的情况，如大小写不敏感，属性名值与等号间有空格等）。此处假设需提取test标签的attr属性值，请自行构建包含该标签的串

10．请使用socket相关函数（非curl）实现如下功能：构造一个post请求，发送到指定http server的指定端口的指定请求路径（如）。请求中包含以下变量：

用户名（username）：温柔一刀
密码（pwd）：&123=321&321=123&
个人简介（intro）：Hello world!

且该http server需要以下cookie来进行简单的用户动作跟踪：

cur_query：you&me
last_tm：…（上次请求的unix时间戳，定为当前请求时间前10分钟）
cur_tm：…（当前请求的unix时间戳）

设置超时为10秒，发出请求后，将http server的响应内容输出。
复制内容到剪贴板
代码:
Function encode($data, $sep = ‘&’){
while (list($k,$v) = each($data)) {
$encoded .= ($encoded ? “$sep” : “”);
$encoded .= rawurlencode($k).”=”.rawurlencode($v);
}
Return $encoded;
}

Function post($url, $post, $cookie){
$url = parse_url($url);
$post = encode($data, ‘&’);
$cookie = encode($cookieArray, ‘;’);
$fp = fsockopen($url['host'], $url['port'] ? $url['port'] : 80, $errno, $errstr, 10);
if (!$fp) return “Failed to open socket to $url[host]“;

fputs($fp, sprintf(”POST %s%s%s HTTP/1.0\n”, $url['path'], $url['query'] ? “?” : “”, $url['query']));
fputs($fp, “Host: $url[host]\n”);
fputs($fp, “Content-type: application/x-www-form-urlencoded\n”);
fputs($fp, “Content-length: ” . strlen($encoded) . “\n”);
fputs($fp, “Cookie: $cookie\n\n”);
fputs($fp, “Connection: close\n\n”);
fputs($fp, “$post \n”);

while (!feof($fp)) {
echo fgets($fp, 128);
}
fclose($fp);
}

$url = ‘[url][/url]’;
$encoded = username=温柔一刀& pwd=
$post = array(
‘username’=> ‘温柔一刀’,
‘pwd => ‘&123=321&321=123&’,
‘intro => ‘Hello world!’
);
$cookie = array(
‘cur_query’ => ‘you&me,
‘last_tm’ => time() - 600,
‘cur_tm ‘=> time()
);

Post($url, $post, $cookie);
11．你用什么方法检查PHP脚本的执行效率（通常是脚本执行时间）和数据库SQL的效率（通常是数据库Query时间），并定位和分析脚本执行和数据库查询的瓶颈所在？
1．脚本执行时间，启用xdebug，使用WinCacheGrind分析。
2．数据库查询，mysql使用EXPLAIN分析查询，启用slow query log记录慢查询。

PHP LAMP Engineer Test Paper
Question 1
What does print out?
A) 3
B) False
C) Null
D) 1
E) 0

Question 2
Which of the following snippets prints a representation of 42 with two decimal places?
A) printf(”%.2d\n”, 42);
B) printf(”%1.2f\n”, 42);
C) printf(”%1.2u\n”, 42);

Question 3
Given
$text = ‘Content-Type: text/xml’;
Which of the following prints ‘text/xml’?
A) print substr($text, strchr($text, ‘:’));
B) print substr($text, strchr($text, ‘:’) + 1);
C) print substr($text, strpos($text, ‘:’) + 1);
D) print substr($text, strpos($text, ‘:’) + 2);
E) print substr($text, 0, strchr($text, ‘:’)
Question 4
What is the value of $a?
$a = in_array('01', array('1')) == var_dump('01' == 1);
?>
A) True
B) False
Question 5
What is the value of $result in the following PHP code?
function timesTwo($int) {
$int = $int * 2;
}
$int = 2;
$result = timesTwo($int);
?>;
Answer: NULL
Question 6
The code below ___________ because ____________.
class Foo {
?>
function bar() {
print "bar";
}
}
?>
A) will work, class definitions can be split up into multiple PHP blocks.
B) will not work, class definitions must be in a single PHP block.
C) will not work, class definitions must be in a single file but can be in multiple PHP blocks.
D) will work, class definitions can be split up into multiple files and multiple PHP blocks.
Question 7
When turned on, ____________ will _________ your script with different variables from HTML forms and cookies.
A) show_errors, enable
B) show_errors, show
C) register_globals, enhance
D) register_globals, inject
Question 8
What will be the output of the following PHP code:
echo count(strlen(""));
?>
Answer: 1
Question 9
What is the best all-purpose way of comparing two strings?
A) Using the strpos function
B) Using the == operator
C) Using strcasecmp()
D) Using strcmp()
Question 10
What is the difference between “print()” and “echo()”?
Answer: print is a function,echo is a language construct