a vectorized version of grep
cw_greplv(pattern, x, ignore.case = FALSE, perl = FALSE, fixed = FALSE,
useBytes = FALSE)character string containing a regular expression
(or character string for fixed = TRUE) to be matched
in the given character vector. Coerced by
as.character to a character string if possible. If a
character vector of length 2 or more is supplied, the first element
is used with a warning. Missing values are allowed except for
regexpr and gregexpr.
a character vector where matches are sought, or an
object which can be coerced by as.character to a character
vector. Long vectors are supported.
if FALSE, the pattern matching is case
sensitive and if TRUE, case is ignored during matching.
logical. Should Perl-compatible regexps be used?
logical. If TRUE, pattern is a string to be
matched as is. Overrides all conflicting arguments.
logical. If TRUE the matching is done
byte-by-byte rather than character-by-character. See
‘Details’.