R: gregexpr(): Find all occurrences of pattern

It is similar to regexpr(), but it finds all occurrences of given pattern.

Usage

gregexpr(pattern, text, ignore.case = FALSE, perl = FALSE,

         fixed = FALSE, useBytes = FALSE)

pattern : Pattern to be searched

text : It is a character vector, where search performs

ignore.case : If it is true, search is case insensitive, if it is false, then search is case sensitive.

perl : If it is true, then perl compatible regular expressions are used, else not.

useBytes : If TRUE the matching is done byte-by-byte rather than character-by-character.
fixed : logical. If TRUE, pattern is a string to be matched as is. Overrides all conflicting arguments.

> gregexpr("to", "If you haven't got anything nice to say about anybody, come sit next to me.")
[[1]]
[1] 34 70
attr(,"match.length")
[1] 2 2
attr(,"useBytes")
[1] TRUE

It finds string “to” in two places, one is at 34^th position and other is at 70^th position.

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