Overview

Library for manipulating FilePaths in a cross platform way.

Installation

filepath comes with Stack. You can add it to your project's package.yaml.

Snippets

(</>)

For example: "/directory" </> "file.ext" -> "/directory/file.ext.

takeBaseName

For example: takeBaseName "/directory/file.ext" -> file. Here it's used in a script to extract the base name of a markdown file and use it to update a corresponding database record:

{-# LANGUAGE OverloadedStrings #-}

import CMark (commonmarkToHtml)
import Data.Text (pack)
import Database.SQLite.Simple (NamedParam ((:=)), close, executeNamed, open)
import System.Directory (listDirectory)
import System.FilePath.Posix (takeBaseName, (</>))

main = do
  conn <- open "haskell-roulette.sqlite3"
  markdownFiles <- listDirectory "markdown"
  mapM_
    ( \x -> do
        md <- readFile $ "markdown" </> x
        let html = commonmarkToHtml [] (pack md)
        executeNamed conn "UPDATE haskell_package SET notes = :notes WHERE name = :name" [":notes" := html, ":name" := (takeBaseName x)]
    )
    markdownFiles
  close conn

takeFileName

For example: takeFileName "/directory/file.ext" -> file.ext. Here it's used in a function to copy a random sampling of files from one directory to another:

module Lib
    ( copyRandomFiles
    ) where

import System.Directory
import System.Directory.Extra
import System.FilePath
import System.Random
import System.Random.Shuffle

copyRandomFiles :: Int -> FilePath -> FilePath -> IO ()
copyRandomFiles numFiles source destination = do randomGenerator <- getStdGen
                                                 sourceFiles <- listFilesRecursive source
                                                 let copyFiles = take numFiles $ shuffle' sourceFiles (length sourceFiles) randomGenerator
                                                 mapM_ (\file -> copyFile file (destination ++ (takeFileName file) )) copyFiles