File: openFile007.hs

package info (click to toggle)
ghc 8.0.1-17
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 55,080 kB
  • ctags: 9,332
  • sloc: haskell: 363,120; ansic: 54,900; sh: 4,782; makefile: 974; perl: 542; asm: 315; python: 306; xml: 154; lisp: 7
file content (18 lines) | stat: -rw-r--r-- 435 bytes parent folder | download | duplicates (12) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
-- !!! check that we don't truncate files if the open fails

import Control.Monad
import System.IO
import System.IO.Error

tmp = "openFile007.out"

main = do
  h <- openFile tmp WriteMode
  hPutStrLn h "hello, world"

  -- second open in write mode better fail, but better not truncate the file
  tryIOError (openFile tmp WriteMode) >>= print
  
  hClose h
  s <- readFile tmp -- make sure our "hello, world" is still there
  putStr s