Creating a temporary directory in Nim (using mkdtemp)

mkdtemp.nim

import posix
from system import `$`

proc mkdtemp*(tmpl: cstring): cstring {.importc, header: "<stdlib.h>".}

proc createTempDirectory*(tmpl: string): string =
  var s = newString(tmpl.len)
  s = tmpl
  if mkdtemp(s.cstring()) == nil:
    raise newException(IOError, "mkdtemp returns null")
  else:
    result = $s

echo createTempDirectory("/tmp/nim.XXXXXX")