PROCEDURE (h: ExtCallHook) OpenExternal* (IN fileName: ARRAY OF CHAR);
   VAR  i, process: INTEGER; cmd: ARRAY [untagged] 128 OF SHORTCHAR;
   BEGIN
      FOR i  := 0 TO LEN(cmd) - 1 DO cmd[i] := 0X END;
      cmd := "xdg-open " + SHORT(fileName$);
      process := LinLibc.popen(cmd, "r");
   END OpenExternal;

FILE *popen(const char *command, const char *type);

MODULE LinLibc ["libc.so.6"];

TYPE
   PtrFILE* = INTEGER;
   PtrSTR* = POINTER TO ARRAY [untagged] OF SHORTCHAR;

...

   PROCEDURE [ccall] popen* (cmd, mode: PtrSTR): INTEGER;

END LinLibc.

      (* something wrong with popen on BlackBox, it traps later on Ta_Basics.Sleep *)
      pr.f := Tl.popen(str, "r");
      IF pr.f = 0 THEN
         res := -1
      ELSE
         pr.fd := Tl.fileno(pr.f);
         IF Tl.fcntl(pr.fd, Tl.F_SETFL, Tl.O_NONBLOCK) < 0 THEN
            res := -1
         ELSE
            res := 0
         END
      END

   VAR   
      process: INTEGER;
      cmd, type: LinLibc.PtrSTR;
      sp: INTEGER;

   PROCEDURE POpen (a, t: ARRAY [untagged] 128 OF SHORTCHAR): INTEGER;
   BEGIN   
      SYSTEM.GETREG(4, sp);
      SYSTEM.PUTREG(4, sp DIV 16 * 16 - X);
      cmd := SYSTEM.VAL(LinLibc.PtrSTR, SYSTEM.ADR(a[0]));
      type := SYSTEM.VAL(LinLibc.PtrSTR, SYSTEM.ADR(t[0]));
      RETURN LinLibc.popen(cmd, type);
   END POpen;
   
   PROCEDURE (h: ExtCallHook) OpenExternal* (IN fileName: ARRAY OF CHAR);
   VAR  res: INTEGER;
   BEGIN
      process := POpen("xdg-open " + SHORT(fileName$) + " &", "r");
      res := LinLibc.pclose(process);
   END OpenExternal;
   
   (*   get error num from linux   *)
   PROCEDURE Errno*;
      VAR
         addr, errno: INTEGER;
   BEGIN
      addr := LinLibc.__errno_location();
      SYSTEM.GET(addr, errno);
      Log.Int(process); Log.Int(errno); Log.Ln;
   END Errno;

EAGAIN* = 11;   (* Try again *)

32-bit version:

   sudo apt-get install libgtk2.0-0 gtk2-engines gtk2-engines-murrine libcanberra-gtk-module
   sudo apt-get install libgnomeui-0 gnome-icon-theme-full

64-bit version:

   sudo dpkg --add-architecture i386
   sudo apt-get update
   sudo apt-get install libgtk2.0-0:i386 gtk2-engines:i386 gtk2-engines-murrine:i386 libcanberra-gtk-module:i386
   sudo apt-get install libgnomeui-0:i386 gnome-icon-theme-full

libc6:i386, libgtk2.0-0:i386, libgnomeui-0:i386, gtk2-engines:i386, gtk2-engines-murrine:i386, libcanberra-gtk-module:i386, gtk2-engines-pixbuf:i386, gnome-themes-standard:i386