Lua does not have regular expressions. Instead it has pattern matching.
The string.gmatch function will take an input string and a pattern.
This pattern describes on what to actually get back.
This function will return a function which is actually an iterator.
Simple matching
for char in ("abc"):gmatch "." do
print(char)
end
for match in ("#afdde6"):gmatch "%x%x" do
print("#" .. match)
end
a
b
c
#af
#dd
#e6
Capture groups
local s = "from=world, to=Lua"
for k, v in string.gmatch(s, "(%w+)=(%w+)") do
print("key: " .. k .. ", value: " .. v)
end
key: from, value: world
key: to, value: Lua
Character classes
| Character class | Matching section |
|---|---|
%a | letters (A-Z, a-z) |
%c | control characters (\n, \t, \r, …) |
%d | digits (0-9) |
%l | lower-case letter (a-z) |
%p | punctuation characters (!, ?, &, …) |
%s | space characters |
%u | upper-case letters |
%w | alphanumeric characters (A-Z, a-z, 0-9) |
%x | hexadecimal digits (\3, \4, …) |
%z | the character with representation 0 |
. | Matches any character |
Any upper-case version of those classes represents the complement of the class.
For instance, %D will match any non-digit character sequence.