/usr/bin/rmic -- why?

[Matthew Zimmerman]

Joel wrote:
> (Apologies for the cross-post.)
> 
> I asked
> 
> 
>>>What are jar, rmiregistry, and who knows what else doing in /usr/bin ?
>>>
>>>I know that everyone just shoves /usr/local/java/sdk/bin (or whatever)
>>>in at the top of $PATH, but I can think of several very good reasons
>>>that is not a good idea. So if there's a good reason, I'd like some
>>>feedback before I post a bug on this.
> 
> 
> Rahul explained
> 
> 
>>they are java related packages. they might have been installed by
>>default. if you dont want remove them. this is not a bug
> 
> 
> and James added
> 
> 
>>They're symlinks into the Red Hat alternatives scheme.
>>man 8 alternatives says:
>>
>>       [...]
>>
>>So they allow you to have a number of Java virtual machines, and easily
>>swap from one to another.
> 
> 
> and then Matthew clarified
> 
> 
>>The Jpackage-style Java installs (including the gcj one included in FC3)
>>use the alternatives(8) system to manage simultaneous installation of 
>>multiple versions.
> 
> 
> Okay, I'll dig into the alternatives man page, although I really didn't
> want to know about that. Don't plan on using it.
> 
> But I did not install any java at all when I installed Fedora. There was
> no javac in the same place. Moreover, on this FC2 install, these are not
> symbolic links. If they're multiply linked, the links are hard. They do
> not show up in /etc/alternatives, nor in anything in /var/lib/alternatives.
> 
> Why are jar and rmic in there at all? Are they being used by the system,
> and if I remove them will something break? How do I find out what else
> to remove?

rpm is your friend! You can use it to figure out what package they're in:

matt at tomis ~ $ rpm -q -f /usr/bin/jar
libgcj-3.3.3-7

and then test removing it to see what other packages depend on it:

matt at tomis /etc/alternatives $ /bin/su
Password:
root at tomis /etc/alternatives $ rpm -e --test libgcj
error: Failed dependencies:
         libgcj.so.4 is needed by (installed) gettext-0.14.1-2.1
         libgcj = 3.3.3 is needed by (installed) libgcj-devel-3.3.3-7
         libgcj >= 3.3.3 is needed by (installed) gcc-java-3.3.3-7

In this case, if I didn't want GNU's java compiler, I could remove 
gcc-java and libgcj-devel, but there might be some other programs that 
use gettext:

root at tomis /etc/alternatives $ rpm -e --test gettext
error: Failed dependencies:
         gettext is needed by (installed) mutt-1.4.1-6

You'll need to remove the --test option to actually remove the packages, 
if you want to do that.

root at tomis /etc/alternatives $ man rpm

-- 
       Matt

       Matthew Zimmerman
       Interdisciplinary Biophysics, University of Virginia
       http://www.people.virginia.edu/~mdz4c/