【转】调试Apache的rewrite规则方法

在旧的Apache的httpd.conf里面是有这样的参数的：

`1`	`RewriteLog` `"/myfolder/mylogfile.log"`

`2`	`RewriteLogLevel 3`

但是在新版本的Apache中，已经取消了RewriteLog这个参数，如果你加上这个参数只会使你的Apache无法启动！新版本的Apache已经把Rewrite模块的日志也写到了Apache的error.log中，只需要我们制定一下输出的log的级别和trace的深度就好了，例如

`1`	`LogLevel alert rewrite:trace3`

LogLevel的级别和深度选择如下表：

Level	Description	Example
`emerg`	Emergencies – system is unusable.	“Child cannot open lock file. Exiting”
`alert`	Action must be taken immediately.	“getpwuid: couldn’t determine user name from uid”
`crit`	Critical Conditions.	“socket: Failed to get a socket, exiting child”
`error`	Error conditions.	“Premature end of script headers”
`warn`	Warning conditions.	“child process 1234 did not exit, sending another SIGHUP”
`notice`	Normal but significant condition.	“httpd: caught SIGBUS, attempting to dump core in …”
`info`	Informational.	“Server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers)…”
`debug`	Debug-level messages	“Opening config file …”
`trace1`	Trace messages	“proxy: FTP: control connection complete”
`trace2`	Trace messages	“proxy: CONNECT: sending the CONNECT request to the remote proxy”
`trace3`	Trace messages	“openssl: Handshake: start”
`trace4`	Trace messages	“read from buffered SSL brigade, mode 0, 17 bytes”
`trace5`	Trace messages	“map lookup FAILED: map=rewritemap key=keyname”
`trace6`	Trace messages	“cache lookup FAILED, forcing new map lookup”
`trace7`	Trace messages, dumping large amounts of data	“\| 0000: 02 23 44 30 13 40 ac 34 df 3d bf 9a 19 49 39 15 \|”
`trace8`	Trace messages, dumping large amounts of data	“\| 0000: 02 23 44 30 13 40 ac 34 df 3d bf 9a 19 49 39 15 \|”

因此我们假如需要调试某个虚拟主机的伪静态的话，我们可以在给虚拟主机的<VirtualHost>配置项或者.htaccess里面加入如下的一段配置：

`1`	`<IfModule mod_rewrite.c>`

`2`	`LogLevel debug rewrite:trace3`

`3`	`</IfModule>`

然后访问一下，error.log里面就会有具体的信息了，可以看到你提交的URL被映射到了哪个文件，进行有针对性的调整。