Ls.hs

module S3.Ls
  ( ls
  ) where

import           Control.Applicative ((<*))
import           Control.Exception   (throwIO)
import           System.Process      (readProcessWithExitCode)
import           Text.Parsec
import           Text.Parsec.String

newtype S3Object = S3Object (String, String, String) deriving (Eq,Show)

ls :: String -> IO [S3Object]
ls bucketName = do
  (_,ok,ng) <- readProcessWithExitCode "s3cmd" ["ls", "s3://" ++ bucketName] []
  if ok == ""
    then throwIO $ userError $ "No bucket found" ++ " " ++ "(" ++ bucketName ++ ")"
    else return $ parseResult ok

result = many line <* eof

parseResult :: String -> [S3Object]
parseResult str = case parse result "ERROR" str of
                Left l   -> error $ show l
                Right xs -> xs

line :: Parser S3Object
line = do
    date <- manyTill anyChar (try (string "   "))
    size <- manyTill anyChar (try (string "   "))
    string "s3://"
    name <- manyTill anyChar (try (char '\n'))
    return $ S3Object (date, size, name)

λ ls "fujimuradaisuke"
[S3Object ("2013-12-27 10:34","6346592","fujimuradaisuke/index (1).tar.gz"),S3Object ("2013-12-27 10:32","6344285","fujimuradaisuke/index.tar.gz"),S3Object ("2013-10-29 13:34","  83864","fujimuradaisuke/otaru.jpg")]