php 를 공부해 보려고 하니 막히는 부분이 한두가지가 아니네요.

조금 많습니다. 총 10가지 인데요..
이 글 읽어보시구 아시는 부분이래도 대답 꼭.. 부탁드립니다.


①

for ($i=0; $i < 5; $i++)

{
    srand((double)microtime()*1000000);
    $arr[$i] = rand(1, strlen($allchars));
    $msg.=substr($allchars, $arr[$i]-1, 1). "  ";
}


②

srand((double)microtime()*1000000);
$arr[0] = rand(1, 5);

$encoded_count = base64_encode($arr[0].$arr[1].$arr[2];

③

$color[0] = imagecolorallocate($im, 255, 255, 255);
$color[1] = imagecolorallocate($im, 0, 168, 255);

④

exec( "top b -n 1 > info.txt");
$fp = fopen("info.txt", "r");

⑤

function exec_thumbnail($defaultpath, $file_name, $max_width, $max_height)

exec( "djpeg -pnm ./upImg/$file_name > ./upThumb/temp_$file_name");
exec( "pnmscale -xy $resizeX $resizeY ./upThumb/temp_$file_name | cjpeg -progressive -optimize -smooth 5 -outfile ./upThumb/$file_name");
unlink("./upThumb/temp_$file_name");



⑥

$page = (!$page) ? 1 : $page;
$startseq = ($page-1) * $pagesize;

$query = "SELECT COUNT(id) FROM gallery";
$rs = mysql_query($query,$connect);
$totalpages = ceil(mysql_result($rs,0,0)/$pagesize);
$prevpage = ($page == 1) ? 1 : ($page-1);
$nextpage = ($page == $totalpages) ? $totalpages : $page + 1;


⑦

$query = "SELECT id,comment FROM gallery_comment WHERE aid='$row[id]' ORDER BY id ASC";



⑧

$spageseq =  ((ceil(($page/10) - 0.01) - 1) * 10) + 1;
$epageseq = $spageseq + 9;
$epageseq = ($epageseq > $totalpages) ? $totalpages : $epageseq;

$ppageseq = $spageseq - 10;
$npageseq = $spageseq + 10;



⑨

$writer = htmlspecialchars(addslashes($writer));
$contents = htmlspecialchars(addslashes($contents));



if (!$file or $HTTP_SERVER_VARS["REQUEST_METHOD"] != 'POST')



⑩

$nowcount = 0;
$addcount = "";
$originalname = str_replace(" ","_",$file_name);
$defaultpath = "./upImg/";
while(1)
{
$file_name = $addcount . $originalname;
if (!file_exists($defaultpath.$file_name)) break;
if ($nowcount) $nowcount++; else $nowcount = 2;
$addcount = $nowcount . "_";
}



$query = "INSERT INTO gallery VALUES (NULL,'+ '+ '$file_name','$writer',now(),'$contents','$pwd')";