=== modified file 'ppio.nim'
--- ppio.nim	2019-04-01 18:02:44 +0000
+++ ppio.nim	2019-04-01 12:45:58 +0000
@@ -1,12 +1,6 @@
 # vim: fileencoding=utf8 ft=nim et sw=2 ts=2 sts=2
+import parseopt
 import os
-import posix
-
-const
-  ERR_PERM = 100
-  ERR_TEMP = 101
-  ERR_EXEC_OTHER = 126
-  ERR_EXEC_ENOENT = 127
 
 proc writeHelp(errorcode: int): void =
   write(stdout, "writeHelp()\n")
@@ -52,18 +46,18 @@
         inc(n)
         if n > argc:
           write(stderr, "Missing argument to " & a & "\n")
-          writeHelp(ERR_PERM)
+          writeHelp(1)
         args.endl = paramStr(n)
       of "-C", "--colors", "--colours":
         for i in 0..3:
           inc(n)
           if n > argc:
             write(stderr, "Missing argument to " & a & "\n")
-            writeHelp(ERR_PERM)
+            writeHelp(1)
           args.color_escapes[i] = paramStr(n)
       else:
         write(stderr, "Unrecognised parameter: \"" & a & "\"\n")
-        writeHelp(ERR_PERM)
+        writeHelp(1)
     else:
       break
     inc(n)
@@ -72,82 +66,12 @@
     inc(n)
   return args
 
-
-proc libc_fatal(msg: string, exitcode=ERR_TEMP): void =
-  var err = posix.errno
-  write(stderr, "fatal: " & msg & " ")
-  write(stderr, posix.strerror(err))
-  write(stderr, "\n")
-  quit(exitcode)
-
-
 proc main(): void =
   var args = posixParseArgs()
   write(stderr, "args: " & repr(args) & "\n")
-
   if len(args.exe) == 0:
     echo "No arguments"
-    writeHelp(ERR_PERM)
-
-  # despite documentation it doesn't search local dir on unix
-  # unless executable name contains /
-  var exe = os.findExe(args.exe[0])
-  if len(exe) == 0:
-    echo "Command not found: " & args.exe[0]
-    quit(ERR_EXEC_ENOENT)
-
-  var
-    pipein: array[0 .. 1, cint]
-    pipeout: array[0 .. 1, cint]
-
-  if posix.pipe(pipein) != 0: libc_fatal("pipe():")
-  if posix.pipe(pipein) != 0: libc_fatal("pipe():")
-
-  var pid = fork()
-  case pid
-  of -1: libc_fatal("fork():")
-  of 0:
-    # Child process
-    if posix.dup2(pipein[0], 0) == -1: libc_fatal("dup2():")
-    if posix.close(pipein[1]) != 0: libc_fatal("close():")
-    if posix.dup2(pipeout[1], 1) == -1: libc_fatal("dup2():")
-    if posix.close(pipeout[0]) != 0: libc_fatal("close():")
-    if posix.execv(exe, allocCStringArray(args.exe)) == -1:
-      var exitcode =
-        if posix.errno == ENOENT: ERR_EXEC_ENOENT
-        else: ERR_EXEC_OTHER
-      libc_fatal("exec():", exitcode)
-    write(stderr, "fatal: exec() did not execute!")
-    quit(ERR_TEMP)
-  else:
-    # Parent process
-    if close(pipein[0]) != 0: libc_fatal("close():")
-    if close(pipeout[1]) != 0: libc_fatal("close():")
-
-    # input: 0 -> pipein[1]
-    # output: pipeout[0] -> 1
-    
-    # TODO: IO loop here
-
-    var
-      status: cint
-      ret: cint
-      err = posix.EINTR
-
-    while err == posix.EINTR:
-      ret = waitpid(pid, status, 0)
-      if ret == -1:
-        err = posix.errno
-      elif ret == pid:
-       #define wait_estatus(w) (WIFSIGNALED(w) ? 128 + WTERMSIG(w) :
-       #                        WEXITSTATUS(w) >= 128 ? 128 : WEXITSTATUS(w))
-       quit(if WIFSIGNALED(status): 128 + WTERMSIG(status)
-            elif WEXITSTATUS(status) >= 128: 128
-            else: WEXITSTATUS(status))
-      else:
-        write(stderr, "fatal: waitpid(): unexpected return value: " & repr(ret))
-        quit(ERR_TEMP)
-    libc_fatal("waitpid():")
+    writeHelp(1)
 
 when isMainModule:
     main()