util.string.find

local start_at, end_at, ... = util.string.find(
    input,
    pattern,
    start_at = 1,
    plain_text = false
)

Type	Name	Description
`string`	input	String to search in
`string`	pattern	Pattern to search for (supports Lua patterns unless plain_text is true)
`int`	start_at	Position to start searching from - negative counts from end
`bool`	plain_text	When true - pattern is treated as plain text, not a pattern

Type	Name	Description
`int`	start_at	Starting index of the match, or `nil` if not found
`int`	end_at	Ending index of the match, or `nil` if not found
`any`	...	Any captured substrings from the pattern

Find the position of a substring

local s, e = util.string.find("hello world", "world")

core.engine.print("info", s, e) -- 7  11

Find the first occurrence of a character

local pos = util.string.find("hello", "l")

core.engine.print("info", pos) -- 3

Search starting from a specific position

local s, e = util.string.find("hello hello", "hello", 7)

core.engine.print("info", s, e) -- 7  11

Find a pattern match position

local s, e = util.string.find("Price: $25.99", "%d+")

core.engine.print("info", s, e) -- 9  10

Find a pattern and capture a group

local s, e, num = util.string.find("hello 123 world", "(%d+)")

core.engine.print("info", s, e, num) -- 7  9  123

Use plain text search to disable pattern matching

local s, e = util.string.find("Cost: $5.00", "$", 1, true)

core.engine.print("info", s, e) -- 7  7

Find a pattern and capture multiple groups

local s, e, word1, word2 = util.string.find("hello world", "(%a+) (%a+)")

core.engine.print("info", word1, word2) -- hello  world

Search from the end using a negative index

local s, e = util.string.find("hello", "l", -3)

core.engine.print("info", s, e) -- 3  3