stringr package provides good string functions.
To search for a string (ignoring case)
one could use
stringr::str_detect('TOYOTA subaru',ignore.case('toyota'))
This works but gives warning
Please use (fixed|coll|regex)(x, ignore_case = TRUE) instead of ignore.case(x)
What is the right way of rewriting it?
You can use regex
(or fix
as @lmo's comments depending on what you need) function to make the pattern as detailed in ?modifiers or ?str_detect (see the instruction for pattern parameter):
library(stringr)
str_detect('TOYOTA subaru', regex('toyota', ignore_case = T))
# [1] TRUE