Re: update-alternatives

[Bas van Gompel <cygwin-apps dot buzz at bavag dot tmfweb dot nl>]

Op Sun, 19 Jun 2005 16:17:13 -0500 schreef Gary R. Van Sickle
in <20050619211718.9E6F4D546@msc-fe01.qinip.net>:
: > -----Original Message-----
[...] On Behalf Of Charles Wilson
: > Sent: Saturday, June 18, 2005 3:06 PM

: > It seems there may be a need for a Debian-like 
: > update-alternatives system on cygwin (see the recent thread 
: > on the main list about making /bin/sh be bash instead of 
: > ash).  Also, such a system would be a better approach than my 
: > cobbled-together postinstall scripts for the many new 
: > versions of automake (ditto libpng).
:  [snip]
:
:  On the symlinks issue: 
:
:  Suppose instead of the current shortcut hybrid scheme, and also instead of
:  copying the executables, and also instead of using NT-only hardlinks (which
:  IIUC aren't Unixoid enough to be "drop-ins" anyway), "Somebody" wrote a
:  "symlink.exe" executable that worked sort of like this:

I happen to have a program I call ``wrap''...

:  - A suitable centralized alternatives database would be kept somewhere, with
:  entries of a "/bin/ls == /bin/alternatives/actual-ls.exe" nature.

It (my ``wrap'') uses files in "/etc/wrap/" + basename(argv[0]).

:  - The "symlink.exe" program would be a one-pager that you copied, under the
:  "assumed name" of the exe you're trying to symlink.  So, as the /bin/ls.exe
:  executable, it would:

My current wrap.exe is 4096 bytes, after stripping.

:    - See that it was executed with the name "/bin/ls.exe"
:    - Look up "/bin/ls.exe" in the database to find which real executable it
:  should run.

The name of the executable to execute is read from /etc/wrap/ls.

:    - spawn() that real executable.

My ``wrap'' uses execvp()...

:  That would solve the "can't run it from a windows command line" problem,
:  wouldn't it?

Absolutely. (I've been using this for unison for a while now.)

If there is interest in this, I'll happily ``ITP'' it...
Just let me know.


L8r,

Buzz.
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