API strlen
From WoWWiki
"strlen" is a shortcut for the standard Lua library function "string.len". They can both be used interchangeably.
string.len(s)
Return the length of the string passed.
> = string.len("Lua")
3
> = string.len("")
0
> = string.len("Lua\000user") -- Lua strings are 8 bit pure so \000 does not terminate
8
This is a Lua function and documented as part of the World of Warcraft API
