昨天正好有个程序的同事问上来的,才发现这个我们平时没有细心了解,于是记录一下!
Checks the truth of a condition. If the condition evaluates to true, then the code indicated in the curly braces is carried out and the request is processed in accordance with the configuration within the following block. The configuration inside the ifdirective is inherited from the previous level.
The condition can be:
the name of a variable; false values are: empty string (“”, or any string starting with “0”;
a comparison of a variable using the = and != operators;
pattern matching with regular expressions:
~ performs a case-sensitive match
~* performs a case-insensitive match (firefox matches FireFox)
!~ and !~* mean the opposite, “doesn’t match”
checking for the existence of a file using the -f or !-f operators;
checking for the existence of a directory using -d or !-d;
checking for the existence of a file, directory or symbolic link using -e or !-e;
checking whether a file is executable using -x or !-x.
http://wiki.nginx.org/HttpRewriteModule
http://blog.c1gstudio.com/archives/434
