Ung dung tap tin htaccess tren may chu Apache

Ban da tung nghe ve tap tin .htaccess tren cac may chu he Unix (FreeBSD, Linux, Solaris, True64...)? Ban biet rang tap tin nay co the dieu khien duoc kha nhieu thu, tham chi thay doi duoc ca thiet lap mac dinh cua may chu Apache. The nhung ban da tan dung duoc bao nhieu lenh trong tap tin nay de lam cho website cua minh manh me, an toan hon?

Tao trang bao loi mang mau sac ca nhan

Trong qua trinh lam viec voi client, neu co loi xay ra (vi du nhu khong tim thay tap tin) thi Apache se bao loi bang mot trang co san hien thi ma so cua loi do, rat khong dep va kho hieu.Voi .haccess thi ban co the tu tao cac trang bao loi hay hon. De lam duoc dieu nay thi trong tap tin .htaccess ban them dong sau:

ErrorDocument ma so loi /Error.html

Trong do ma so loi la ma so cua loi phat sinh, sau day la nhung loi hay gap:

- 401 - Authorization Required (can password de truy nhap)
- 400 - Bad request (Loi do yeu cau)
- 403 - Forbidden (khong duoc vao)
- 500 - Internal Server Error (loi server)
- 404 - Wrong page (loi trang, khong tim thay...)

Con Error.html la trang web ma ban muon hien thi khi loi phat sinh, co the dua vao tap tin nay noi dung hay do hoa gi tuy ban, chang han lien ket tro ve trang chinh cua trang web.

Vi du: ErrorDocument 404 /Error.html hoac: ErrorDocument 500 /loi/500.html

Bay gio ban hay tai (upload) 2 tap tin .htaccess va Error.html len hosting cua minh.

Chong an cap bang thong (bandwidth)

Thong thuong nhung dich vu luu tru web chi cung cap cho ban mot luong du lieu luan chuyen (data transfer) nhat dinh hang thang va khi ban su dung het luong du lieu nay, website cua ban se tu dong bi dong cua. Ban se phai tra them tien cho luong bang thong vuot qua hoac phai buoc long cho den thang sau.

Neu hinh anh, du lieu, …cua ban bi cac website khac “an cap” (bang cac thu thuat don gian) lam cho luong du lieu luan chuyen cua ban tang len, thi co nghia la ban se phai tra tien cho cai ma ban khong su dung. Su dung tap tin .htaccess la mot giai phap hoan hao, de ngan chan viec su dung hinh anh trai phep tren website cua ban. Ban chi viec dua vao tap tin .htaccess noi dung sau:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?trangweb\.com/.*$ [NC]
RewriteRule \.(gif|jpg)$ - [F]

O doan ma tren toi su dung module Rewrite cua may chu Apache, ban chi viec thay doi trangweb.com thanh dia chi website cua minh.

Co the su dung mot hinh anh nao do canh cao nhung ke “an trom” bang thong, ban dung dong lenh sau:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?trangweb\.com/.*$ [NC]
RewriteRule \.(gif|jpg)$ http://www.trangweb.com/diehotlinker.jpg [R,L]

Khong cho hien danh sach tap tin trong thu muc

Trong truong hop mot thu muc nao do khong co tap tin index hoac default, Apache se hien thi mot danh sach liet ke nhung tap tin co trong thu muc do. Tuy nhien neu day la nhung tai lieu nhay cam, ban khong muon nguoi khac thay, hay them lenh sau vao tap tin .htaccess

Options –Indexes

Thay the trang index

Thong thuong khi truy nhap vao mot trang web, Apache se tim tap tin index.htm hoac default.htm tra ket qua ve cho trinh duyet, ban co the dung .htaccess thay doi mac dinh nay.

DirectoryIndex index.php index .php3 messagebrd.pl index.html index.htm

Voi dong lenh nay thi tat ca cac tap tin duoc liet ke se duoc tim theo thu tu khi co yeu cau toi thu muc hien hanh, trang nao duoc tim thay dau tien se thanh trang index cua thu muc.

Cam/han che IP truy nhap

Mot so nguoi muon lam ngap (flood) trang web cua ban, viec can lam la ngan cam nhung IP cua nhung nguoi nay truy nhap vao trang web, ban them doan ma sau vao .htaccess: deny from 203.262.110.20; cho phep IP truy nhap: allow from 203.262.110.20.

Neu ban chi viet IP duoi dang: 203.262.110 thi se cam tat ca IP trong dai tu 203.262.110.1 den 203.262.110.254.

Su dung dong lenh sau: Deny from all se cam tat ca moi truy nhap den cac trang web trong thu muc, tuy nhien cac tap tin trong do van co the duoc su dung tu ben ngoai thong qua cac lenh dang require hay include (trong lap trinh PHP), co the xem them ma nguon cua PHPBB forum,IBF... de hieu ro hon.

Tu dong chuyen den dia chi moi (Redirection)

Ban chuyen trang web cua minh den dia chi moi nhung khong phai ai cung biet dieu nay, redirect truy nhap tu xa mot cach don gian bang lenh sau:

Redirect/olddirectory http://www.trangwebmoi.com/thumucmoi

Tuy bien duoi tap tin

Thong thuong, tuy thuoc vao ngon ngu lap trinh web ma ban su dung tap tin se co phan mo rong khac nhau nhu: html, htm, asp, aspx, php, cgi, …Tuy nhien neu su dung .htaccess ban co the tac dong vao may chu Apache, Apache se goi den tap tin cua ban va tra ve cho trinh duyet web cua nguoi dung voi phan mo rong do ban quy dinh trong .htaccess. Ban su dung doan lenh sau trong tap tin .htaccess:

RewriteEngine on
RewriteRule (.*)\.dll$ $1.html

Html la phan mo rong thuc su cua nhung tap tin tren website, dll la phan mo rong do ban lua chon. Luu y trong lien ket tren trang web, ban phai goi dung duong dan den tap tin voi phan mo rong moi (o tren la dll), vi du http://www.lbvmt.net/index.dll

Luu y khi su dung tap tin .htaccess:

- Chi ap dung tren may chu Apache da bat che do .htaccess, neu chua ban hay thu lien he voi nha cung cap dich vu hosting.

- De tao ra tap tin nay ban co the su dung ngay chuong trinh Notepad cua Windows: chon che do save as voi ten .htaccess, nhung khi luu nho bo duoi txt.

-.htaccess chi co tac dung doi voi nhung tap tin ngang hang (trong cung thu muc voi no) hoac thu muc con. Voi thu muc, no chi co tac dung trong thu muc chua no va thu muc con, con vo tac dung voi thu muc me (parent directory).

- Ban co the dung mot so chuong trinh FTP (Leaf FTP, WS FTP, Cute FTP) de tai tap tin .htaccess len hosting cua minh voi che do ASCII, neu no khong hoat dong ban thu CHMOD voi gia tri 644.

Tac gia Hoang Nghia Hanh (Dang tren tap chi BCVT&CNTT)