[tex-live] Installation on an USB Stick

Reinhard Kotucha reinhard.kotucha at web.de
Tue Dec 1 00:55:02 CET 2015

On 2015-11-30 at 19:59:39 +0100, Herbert Voss wrote:

 > Am 30.11.2015 um 19:36 schrieb Reinhard Kotucha:
 > > On 2015-11-30 at 18:01:10 +0100, Herbert Voss wrote:
 > >
 > >   > Hello all,
 > >   > am I right that it is not possible to disable
 > >   > under Linux the creation of symlinks when installing TL
 > >   > on a vfat formatted stick?
 > >   > In the installer I didn't found the (old) option L
 > >   > for enable/disable the creation of symlinks.
 > >
 > > symlinks are disabled by default.  They can be enabled in the
 > > options menu.
 > >
 > > You can see in the main menu which options are set.
 > Reinhard,
 > I tried from DVD TL2015
 > install-tl --portable
 > I changed the main directory to /USB  which was a vfat formatted
 > stick and failed with the first bin/ package a2ping where the
 > installer tries to set the link.

Ouch!  Looks like a bug.  It seems that the installer just determines
on which operating system it's running but this isn't enough.

Siep, Norbert, Karl,
there is a function SymlinkOrCopy() in updmap.pl, line 598ff.

  When invoked from Windows it copies the file (no way to create
  symlinks), on other systems it tries to create a symlink first and
  if it fails, it copies the file.  Thus it does the right thing even
  if a particular file system doesn't support symlinks though they are
  supported by the operating system currently in use.

  Maybe it's best to move the function to TeXLive::Utils in order to
  avoid code duplication.  The function SymlinkOrCopy() can be used to
  create the symlinks in bin/<platform> except in bin/win32.

BTW, all this has nothing to do with the L option.  The latter is
supposed to create symlinks in directories which are already in PATH
(default is /usr/local/bin) and is unrelated to symlinks within TeX
Live's bin directory (like latex -> pdftex).  The sole purpose of the
L option is to allow people who are completely unfamiliar with their
operating system and unable to adapt PATH to install TeX Live though.
It's definitely not recommended.

Herbert, if you have time to experiment, you can also try UDF instead
of VFAT.  It's platform independent and supports symlinks.  AFAIK it
works fine on Windows.  When we discussed it a few years ago Norbert
said that it wasn't available on OS/X, don't know whether it's still
true.  On Unix I encountered problems with file ownerships.  You can
only update TL as root.  This is better than a system on a DVD, where
you can't update at all, of course.  But your personal directories
(including TEXMFCONFIG and TEXMFVAR) must be world-writable because
you have different UIDs on different machines.  This is certainly not
desirable on multi-user systems, but VFAT isn't better in this respect
either.  With UDF you can have a system with symlinks on Unix which
works on Windows too, at least.

IMO it's worthwhile to investigate.  We discussed it already some
time ago but gave up when Norbert said that UDF is not supported by
OS/X.  Maybe it's just a matter of time.  Wouldn't it be great to have
TeX Live on a USB stick which works on all systems and even supports
symlinks on systems which supports them?


Reinhard Kotucha                            Phone: +49-511-3373112
Marschnerstr. 25
D-30167 Hannover                    mailto:reinhard.kotucha at web.de

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