fork(1) download
  1. library(stringr)
  2.  
  3. x <- c('123456789', 'kfasdf 3456789asdf', 'a 1')
  4. y <- c('12345 789', '1 9', 'a 678a')
  5.  
  6. str_extract(x, regex('(?=[ \\d]{9}(.*$))[ ]*\\d+\\1$'))
  7. str_extract(y, regex('(?=[ \\d]{9}(.*$))[ ]*\\d+\\1$'))
Success #stdin #stdout 0.24s 42652KB
stdin
Standard input is empty
stdout
[1] "123456789"     "  3456789asdf" "        1"    
[1] NA NA NA