PHP中常见问题总结

<?php
// 自 PHP 3 起可用
print $HTTP_POST_VARS['username'];
// 自 PHP 4.1.0 起可用
print $_POST['username'];
print $_REQUEST['username'];
import_request_variables('p', 'p_');
print $p_username;
// 如果PHP指令 register_globals = on 时可用。不过自PHP 4.2.0 起默认值为 register_globals = off不提倡使用此种方法。
print $username;
?>

if(file_exists('temp.php'))
{
$x=r('temp.php');
@eval("\$a = $x;");
}
if(!is_array($a)){
#重新构造数组A
$a=array(array("af"=>"fsdf"),"f"=>"df");
}
w('temp.php',var_export($a,true));
var_dump($a);
读取，写入文档数据
function r($file_name)
{
$filenum=@fopen($file_name,"r");
@flock($filenum,LOCK_SH);
$file_data=@fread($filenum,filesize($file_name));
@fclose($filenum);
return $file_data;
}
function w($file_name,$data,$method="w")
{
$filenum=@fopen($file_name,$method);
flock($filenum,LOCK_EX);
$file_data=fwrite($filenum,$data);
fclose($filenum);
return $file_data;
}

<form action="" method=post enctype="multipart/form-data">
<input type=file name=usefile[]>
<input type=file name=usefile[]>
<input type=file name=usefile[]>
</form>
这样，在服务器端做以下测试
echo "<pre>";
print_r($_FILES);
echo "</pre>";

<form action="" method=post enctype="multipart/form-data">
<input type=file name=usefile_a>
<input type=file name=usefile_b>
<input type=file name=usefile_c>
</form>
在服务器端做同样测试：
echo "<pre>";
print_r($_FILES);
echo "</pre>";

把通过GET或POST方式提交的变量转化为全局变量:
foreach($_GET as $key=>$value){
$$key=$value;
}
foreach($_POST as $key=>$value){
$$key=$value;
}

<?php
function pmyoutput(&$a)
{
if (is_array($a))
{
array_walk($a,'pmyoutput');
}
else
{
$a = stripslashes($a);
}
}
function pmyinput(&$a)
{
if (is_array($a))
{
array_walk($a,'pmyinput');
}
else
{
$a = addslashes($a);
}
}
if (phpversion() < '4.1.0')
{
isset($HTTP_SESSION_VARS) ? $GLOBALS['_SESSION'] = &$HTTP_SESSION_VARS : '';
isset($HTTP_SERVER_VARS) ? $GLOBALS['_SERVER'] = &$HTTP_SERVER_VARS : '';
isset($HTTP_ENV_VARS) ? $GLOBALS['_ENV'] = &$HTTP_ENV
_VARS : '';
isset($HTTP_FILES_VARS) ? $GLOBALS['_FILES'] = &$HTTP_FILES_VARS : '';
if (get_magic_quotes_gpc() == 1)
{
isset($HTTP_GET_VARS) ? $GLOBALS['_GET'] = &$HTTP_GET_VARS : '';
isset($HTTP_POST_VARS) ? $GLOBALS['_POST'] = &$HTTP_POST_VARS : '';
isset($HTTP_COOKIE_VARS) ? $GLOBALS['_COOKIE'] = &$HTTP_COOKIE_VARS : '';
}
else
{
isset($HTTP_GET_VARS) ? pmyinput($HTTP_GET_VARS) : '';
isset($HTTP_POST_VARS) ? pmyinput($HTTP_POST_VARS) : '';
isset($HTTP_COOKIE_VARS) ? pmyinput($HTTP_COOKIE_VARS) : '';
$GLOBALS['_GET'] = &$HTTP_GET_VARS;
$GLOBALS['_POST'] = &$HTTP_POST_VARS;
$GLOBALS['_COOKIE'] = &$HTTP_COOKIE_VARS;
}
$GLOBALS['_REQUEST'] = array_merge($_GET, $_POST, $_COOKIE);
}
else
{
if (get_magic_quotes_gpc() != 1)
{
isset($_GET) ? pmyinput($_GET) : '';
isset($_POST) ? pmyinput($_POST) : '';
isset($_COOKIE) ? pmyinput($_COOKIE) : '';
isset($_REQUEST) ? pmyinput($_REQUEST) : '';
}
}
?>

unction Get_Date($sent)
{
//return local area time now it's available DSONet @ 2003-8-7 17:29
$months=array('一月','二月','三月','四月','五月','六月','七月','八月','九月','十月','十一月','十二月');
$weeks = array('星期日','星期一','星期二','星期三','星期四','星期五','星期六');
list($sec,$min,$hour,$mon,$year,$mday,$wday,$yday) = explode(" ",date("s i H n Y j w z",date($sent)));
list($Tsec,$Tmin,$Thour,$Tmon,$Tyear,$Tmday,$Tyday) = explode(" ",date("s i H n Y w z",time()));
$mon-=1;
//$mday.="日";
$date="{$year}年$months[$mon]{$mday}日";
if ($year == $Tyear)
{
$Cyday = $Tyday - $yday;
if ($Cyday == 0) { $date = "今天"; }
else if ($Cyday == 1) { $date = "昨天"; }
else if ($Cyday == 2) { $date = "前天"; }
else if ($Cyday <= 7) { $date = "$weeks[$wday]";}
return $date;
}
return $date;
//return date("M d Y H:i",$sent);
}
另外如果您的php无法接受中文，有以下方法:
//htmlentities maybe can't supported to chinese gb2312 DSONet @ 2003-8-7 17:00
//$email = htmlentities($in['email']);
//following is ok
$subject = htmlspecialchars($in['subject'],ENT_QUOTES);
还有这个正则表达式可以去掉(\")
$txt=ereg_replace("([\r\n])","",$txt);
//DSONet @ 2003-8-8 12:09
//cause $txt include some interpunction like \" so must clearn these dirty words.I don't konw why it has these bad words now .js?
$txt=ereg_replace("[\\](\")","\"",$txt);