modrewrite配置文档学习笔记

1.环境变量:

例子:

SCRIPT_NAME=/sw/lib/w3s/tree/global/u/rse/.www/index.html
SCRIPT_FILENAME=/u/rse/.www/index.html
SCRIPT_URL=/u/rse/
SCRIPT_URI=http://en1.engelschall.com/u/rse/

2:RewriteBase
描述：设定基于目录的重写规则的Base url.
Syntax: RewriteBase URL-path
Context: directory, .htaccess
Override: FileInfo
Status: Extension
Module: mod_rewrite
这个一般不太需要管它.
3.RewriteCond
用法: RewriteCond Teststring Pattern
这里是Teststring里用到的一些内置变量.
HTTP headers: connection & request:
HTTP_USER_AGENT
HTTP_REFERER
HTTP_COOKIE
HTTP_FORWARDED
HTTP_HOST
HTTP_PROXY_CONNECTION
HTTP_ACCEPT
REMOTE_ADDR
REMOTE_HOST
REMOTE_PORT
REMOTE_USER
REMOTE_IDENT
REQUEST_METHOD
SCRIPT_FILENAME
PATH_INFO
QUERY_STRING
AUTH_TYPE

DOCUMENT_ROOT
SERVER_ADMIN
SERVER_NAME
SERVER_ADDR
SERVER_PORT
SERVER_PROTOCOL
SERVER_SOFTWARE
TIME_YEAR
TIME_MON
TIME_DAY
TIME_HOUR
TIME_MIN
TIME_SEC
TIME_WDAY
TIME
API_VERSION
THE_REQUEST
REQUEST_URI
REQUEST_FILENAME
IS_SUBREQ
HTTPS

#你可以在规则前加"!"取反.
#这是一些常见的特殊的规则。你可以使用他们来取代一些表达式:

* 'CondPattern’ (lexicographically follows)
* ‘=CondPattern’ (lexicographically equal)
* ‘-d’ (is directory) 测试是否是目录.
* ‘-f’ (is regular file) 测试是否是常规文件.
* ‘-s’ (is regular file, with size)
* ‘-l’ (is symbolic link)
* ‘-F’ (is existing file, via subrequest)
* ‘-U’ (is existing URL, via subrequest)

你可以为规则后设置[flags]选项作为第三个参数.常见的有:
You can also set special flags for CondPattern by appending [flags] as the third argument to the RewriteCond directive, where flags is a comma-separated list of any of the following flags:

# ‘nocase|NC’ (no case)
# ‘ornext|OR’ (or next condition)
例如:
RewriteCond %{REMOTE_HOST} ^host1.* [OR]
RewriteCond %{REMOTE_HOST} ^host2.* [OR]
RewriteCond %{REMOTE_HOST} ^host3.*
RewriteRule …some special stuff for any of these hosts…

如下例:
RewriteCond %{HTTP_USER_AGENT} ^Mozilla.*
RewriteRule ^/$ /homepage.max.html [L]

RewriteCond %{HTTP_USER_AGENT} ^Lynx.*
RewriteRule ^/$ /homepage.min.html [L]

RewriteRule ^/$ /homepage.std.html [L]
用Mozilla类的浏览器访问时会带你到homepage.max.html,这里支持所有特性。用Lynx来浏览时，带你到纯文本页(homepage.min.html),默认情况下会访问一个叫homepage.std.html的页.

4.RewriteEngine:
使用:
RewriteEngine On|Off
如果存在.htaccess的文件，应当显式地指明RewriteEngine On.
因为默认情况下.htaccess的RewriteEngine项是Off的。因此如果想用.htaccess来设置rewrite,文件头一行一般都需要RewriteEngine On

5.RewriteLock:
供rewrite-mapping程序同步使用的锁文件。
使用:
RewriteLock file-path

6.RewriteLog:
设定日志文件.如果不是以”/”开头，则是指相对ServerRoot的相对路径.
使用:
RewriteLog file-path

7.RewriteLogLevel:
设定日志记录级别。
使用:
RewriteLogLevel level
默认:

8.RewriteMap:
使用Mapping.
它的上下文是Server config 和Virtual host
使用:
RewriteMap Mapname MapType:Mapsource
例如:
在httpd.conf中配置:
#RewriteMap exampleMap txt:/path/to/file/map.txt
#RewriteRule ^/ex/(.*) ${exampleMap:$1}
而map文件的格式有这个几个:
1.txt类型的map文件:
#Standard Plain txt:
#map.txt
#maptype:txt
Ralf.S.Engelschall rse # Bastard Operator From Hell
Mr.Joe.Average joe # Mr. Average

2.Randomized Plain Text
#maptyp:rnd
static www1|www2|www3|www4
dynamic www5|www6

配置:
RewriteMap servers rnd:/path/to/mapfile/map.txt
RewriteRule ^/(.*.(png|gif|jpg)) http://${servers:static}/$1 [NC,P,L]
RewriteRule ^/(.*) http://${servers:dynamic}/$1 [P,L]

3.dbm
这里提供了一个txt2dmb程序。
!/path/to/bin/perl
##
## txt2dbm — convert txt map to dbm format
##

use NDBM_File;
use Fcntl;

($txtmap, $dbmmap) = @ARGV;

open(TXT, “<$txtmap") or die "Couldn't open $txtmap!n";
tie (%DB, 'NDBM_File', $dbmmap,O_RDWR|O_TRUNC|O_CREAT, 0644)
or die "Couldn't create $dbmmap!n";

while () {
next if (/^s*#/ or /^s*$/);
$DB{$1} = $2 if (/^s*(S+)s+(S+)/);
}

untie %DB;
close(TXT);

用法:
$ txt2dbm map.txt map.db

4.内置函数:
map:int map-source:internal apache functions
functions有:toupper,tolower,escape,unescape

5.外部程序:
maptyp:prg map source:外部程序的路径.
示例:
#!/usr/bin/perl
$| = 1;
while () {
# …put here any transformations or lookups…
print $_;
}

9.RewriteOptions
用法:
RewriteOptions rewriteoptions
default :
rewriteoptions maxRedirects=10
上下文:
server config,virtual host,.htaccess directory
rewriteoptions可以是下面两个值:
inherit:从上一级配置继承.
MaxRedirects=num(10,15,,,,,等等)

10.RewriteRule:
这是mod_rewrite中用得最多的语句了(”the real rewriting workhorse”);
用法:
RewriteRule pattern Substitution [Flags]

Quantifiers:
? 0 or 1 occurrences of the preceding text
* 0 or N occurrences of the preceding text (N > 0)
+ 1 or N occurrences of the preceding text (N > 1)

Grouping:
(text) Grouping of text
(used either to set the borders of an alternative as above, or
to make backreferences, where the Nth group can
be referred to on the RHS of a RewriteRule as $N)

Anchors:
^ Start-of-line anchor
$ End-of-line anchor

Escaping:
char escape the given char
(for instance, to specify the chars “.[]()” etc.)

一些技巧:
1. back-references ($N) to the RewriteRule pattern
2. back-references (%N) to the last matched RewriteCond pattern
3. server-variables as in rule condition test-strings (%{VARNAME})
4. mapping-function calls (${mapname:key|default})

关于Flags:
# ‘chain|C’ (chained with next rule)
# ‘cookie|CO=NAME:VAL:domain[:lifetime[:path]]’ (set cookie)
# ‘env|E=VAR:VAL’ (set environment variable)
# ‘forbidden|F’ (force URL to be forbidden)
# ‘gone|G’ (force URL to be gone)
# ‘last|L’ (last rule)
# ‘next|N’ (next round)
# ‘nocase|NC’ (no case)
# ‘noescape|NE’ (no URI escaping of output)
例如:
RewriteRule /foo/(.*) /bar?arg=P1%3d$1 [R,NE]
这将会将’/foo/zed’ 转向到’/bar?arg=p1=zed’
# ‘nosubreq|NS’ ( not for internal sub-requests)
# ‘proxy|P’ (force proxy)

Note: mod_proxy must be enabled in order to use this flag.
# ‘passthrough|PT’ (pass through to next handler)
(例如:
RewriteRule ^/abc(.*) /def$1 [PT]
Alias /def /ghi

# ‘qsappend|QSA’ (query string append)
# ‘redirect|R [=code]’ (force redirect)
# ’skip|S=num’ (skip next rule(s))
# ‘type|T=MIME-type’ (force MIME type)