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Author Topic: Busybox symlinks into /usr/bin  (Read 2038 times)

Offline AmatCoder

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Busybox symlinks into /usr/bin
« on: April 27, 2012, 04:14:28 PM »
I'm wondering:
Is there any reason to put some busybox symlinks into /usr/bin and others into /bin?
Should not they all be in /bin?

Problem arise when I load coreutils.tcz, xz.tcz or similar... They do not replace some busybox equivalents.

Offline gerald_clark

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Re: Busybox symlinks into /usr/bin
« Reply #1 on: April 27, 2012, 05:46:30 PM »
If you want to find programs in /usr/local/bin and /usr/local/sbin first, change your PATH.

Offline AmatCoder

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Re: Busybox symlinks into /usr/bin
« Reply #2 on: April 27, 2012, 07:28:44 PM »
Consider following sequence:
Code: [Select]
tc@box:~$ echo $PATH
/home/tc/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/apps/bin:/etc/sysconfig/tcedir/ondemand

tc@box:~$ tce-load -i coreutils
libattr.tcz: OK
libcap.tcz: OK
gmp.tcz: OK
attr.tcz: OK
acl.tcz: OK
coreutils.tcz: OK

tc@box:~$ which install
/usr/local/bin/install

tc@box:~$ install --help
BusyBox v1.19.4 (2012-03-09 02:27:21 UTC) multi-call binary.

Usage: install [-cdDsp] [-o USER] [-g GRP] [-m MODE] [SOURCE]... DEST
[...]
It's wrong.

But if I open another terminal it is correct:
Code: [Select]
tc@box:~$ install --help
Usage: install [OPTION]... [-T] SOURCE DEST
  or:  install [OPTION]... SOURCE... DIRECTORY
  or:  install [OPTION]... -t DIRECTORY SOURCE...
  or:  install [OPTION]... -d DIRECTORY...

This install program copies files (often just compiled) into destination
locations you choose.  If you want to download and install a ready-to-use
package on a GNU/Linux system, you should instead be using a package manager
like yum(1) or apt-get(1).
[...]

tc@box:~$ which install
/usr/local/bin/install

and this only happens with busybox symlinks into /usr/bin .

Example in first terminal with 'cp' (busybox symlink is into /bin):
Code: [Select]
tc@box:~$ cp --help
[...]
Report cp bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report cp translation bugs to <http://translationproject.org/team/>
For complete documentation, run: info coreutils 'cp invocation
It's correct.

Offline gerald_clark

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Re: Busybox symlinks into /usr/bin
« Reply #3 on: April 27, 2012, 07:34:17 PM »
hash -r

Offline Rich

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Re: Busybox symlinks into /usr/bin
« Reply #4 on: April 27, 2012, 07:48:02 PM »
Hi gerald_clark
Thanks for that concise yet terse answer, I was not aware of this. For those looking for an explanation of what
this means, this seems to cover it pretty nicely:
http://crashingdaily.wordpress.com/2008/04/21/hashing-the-executables-a-look-at-hash-and-type/

Offline AmatCoder

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Re: Busybox symlinks into /usr/bin
« Reply #5 on: April 27, 2012, 07:51:45 PM »
Yes, that works but it can be avoided if all busybox symlinks were in /bin (mostly are...)

User expects to use GNU version of coreutils right away of loading coreutils extension without to reset the hash table...

Offline gerald_clark

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Re: Busybox symlinks into /usr/bin
« Reply #6 on: April 27, 2012, 08:03:41 PM »
It is not the location of the symlink, but rather that you had previously run the command prior to loading coreutils.

Offline Rich

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Re: Busybox symlinks into /usr/bin
« Reply #7 on: April 27, 2012, 08:06:24 PM »
Hi AmatCoder
The same thing would still have happened even if the busybox link were in /bin.

Offline curaga

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Re: Busybox symlinks into /usr/bin
« Reply #8 on: April 28, 2012, 01:11:45 AM »
Yes, it wouldn't matter if they were only in /bin, the same would happen. As for why some are in /usr/bin, it's the default path in bb make install, usually because some packages expect (hardcode) them in that dir.
The only barriers that can stop you are the ones you create yourself.

Offline roberts

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Re: Busybox symlinks into /usr/bin
« Reply #9 on: April 28, 2012, 08:38:18 AM »
Wouldn't it be as simple as adding "hash -r"  to the coreutils startup script?
10+ Years Contributing to Linux Open Source Projects.

Offline curaga

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Re: Busybox symlinks into /usr/bin
« Reply #10 on: April 28, 2012, 09:00:10 AM »
No, that would do it in a different shell session.
The only barriers that can stop you are the ones you create yourself.

Offline AmatCoder

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Re: Busybox symlinks into /usr/bin
« Reply #11 on: April 28, 2012, 05:58:00 PM »
First, thanks to all for replies.

Second, yes, I was wrong with 'precedence-path' assumption... :-[ Some tests I made confused me.

Quote
Wouldn't it be as simple as adding "hash -r"  to the coreutils startup script?
Quote
No, that would do it in a different shell session.

With bash is possible override this behaviour in order that all shell sessions do not use hash table (with 'set +h'  into ./bashrc or editing $SHELLOPTS environment variable) but with ash I guess there are no way. :'(

Offline curaga

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Re: Busybox symlinks into /usr/bin
« Reply #12 on: April 29, 2012, 12:14:22 AM »
Doing that costs performance (requires a path lookup for every command), moreso on slower systems, so I'm against disabling the hash table by default.
The only barriers that can stop you are the ones you create yourself.