Extracting text after last period in string [duplicate]

I realize this question probably seems painfully simple to most regular expression masters, but reviewing similar questions has not yielded a solution.

I have a vector of e-mail addresses called email and would like to extract the text after the final period in each one. For the sake of example,

email<-c("[email protected]", "[email protected]", "[email protected]")

I have tried:

grep("[\.][a-zA-Z]*?$", email, value=T)

This gets me the error message:

Error: '.' is an unrecognised escape in character string starting ""."`

Removing the escape character on the other hand

grep("[.][a-zA-Z]*?$", email, value=T)

returns the entire e-mail address as does:

grep("\\.[a-zA-Z]*$", email, perl=T, value=T)

I'd really appreciate help at this point.

If you need to extract the string after the last period (.), try with sub

sub('.*\\.', '', email)
#[1] "com" "com"

data

email <- c('[email protected]', 'xxx$xxxx.com')

Try

email <- c("[email protected]", "[email protected]")
sapply(strsplit(email, split= ".", fixed = TRUE), tail, 1L)

# [1] "com" "com"

Also, as pointed out by @RichardScriven, tools has a tailor-made function for what you're trying to do specifically:

library(tools)
file_ext(email)
# [1] "com" "com"