Re: regexp in lua

[Romulo Bahiense <romulo@...>]

Walter Rodrigo de Sá Cruz wrote:
> Hey guys! I get in this list today :)
>
> In PHP, I can make this with preg:
>
>
> preg_match('/^(\/var\/www\/)(.*)/', '/var/www/files/index.php', 
> $array_result);
>
> and I will get:
> $array_result[0] = /var/www/files/index.php
> $array_result[1] = /var/www/
> $array_result[2] = files/index.php
>
> How can I get a similar thing in Lua ?

array_result = { string.find('/var/www/files/index.php', 
'^(/var/www/)(.*)') }

The differences:

- Lua's array/list/table starts at index 1, and not 0.
- string.find returns where the match begins and end, so, 
array_result[1] is equal to 1, array_result[2], in this case, is equal 
to 24, array_result[3] is the first match ("/var/www/") and 
array_result[4], the second match: "files/index.php"
- To use it as array (list/table), you need to enclose the call into 
brackets: "{" and "}", but usually you would, instead:

local s,e,path,file = string.find('/var/www/files/index.php', 
'^(/var/www/)(.*)')

Note1: It is much more cheap to return multiple values than create a table
Note2: Most prefer to name the locals as: "local _,_,path,file = ..."
Note3: In the not-yet-released Lua 5.1, you could use the built-in 
function "select" to skip those unnecessary values: "local path,file = 
select(3,string.find(....)))"


Hope it helps :)

--rb