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N_BaH

Member

Registered: 2015-12-30

Posts: 84

[solved] bash PATH has extra paths

hi,

bash's PATH contains extra paths to site_perl, vendor_perl and core_perl.

$ ps h -p $PPID
12780 ?        Ss     0:00 urxvt
$ echo "${PATH//:/$'\n'}" | sort | uniq -c
      1 /usr/bin
      1 /usr/bin/core_perl
      1 /usr/bin/site_perl
      1 /usr/bin/vendor_perl
      1 /usr/local/bin
      1 /usr/local/sbin

$ ps h -p $PPID
24573 ?        00:00:07 tmux: server
$ echo "${PATH//:/$'\n'}" | sort | uniq -c
      1 /usr/bin
      2 /usr/bin/core_perl
      2 /usr/bin/site_perl
      2 /usr/bin/vendor_perl
      1 /usr/local/bin
      1 /usr/local/sbin

first, I can't find where it comes from.
second, why are they "doubled" in tmux ?
and finally, are these perl's paths really worth ?

Last edited by N_BaH (2019-01-14 12:46:00)

ayekat

Member

Registered: 2011-01-17

Posts: 1,589

Re: [solved] bash PATH has extra paths

first, I can't find where it comes from.

The shell environment is set by /etc/profile and the shell snippet files in /etc/profiles.d/; the shell sources those files during login.
In this particular case, it's /etc/profiles.d/perlbin.sh.

second, why are they "doubled" in tmux ?

If you look at /etc/profiles.d/perlbin.sh, you'll notice that it simply appends the paths to $PATH without checking if the paths are already part of $PATH (typically, those shell snippets don't expect to be sourced multiple times).

The problem is that tmux appears to launch a login shell, and even though $PATH is already fully populated at that point, the login shell sources /etc/profile again, and everything is added a second time.

(this does not happen for /usr/bin, /usr/local/bin and /usr/local/sbin, because /etc/profile actually checks for duplicates—but the others don't)

and finally, are these perl's paths really worth ?

They contain perl scripts. However, I don't quite know why they have to be dropped in a separate directory and not just in /usr/bin… I guess there is some (unknown-to-me) legacy reason.

Last edited by ayekat (2019-01-14 10:51:14)

---

pkgs │ hacks │ cfg │ blag

N_BaH

Member

Registered: 2015-12-30

Posts: 84

Re: [solved] bash PATH has extra paths

In this particular case, it's /etc/profiles.d/perlbin.sh.

thank you.

I guess it should be sourced, but I can't find where.

grep -r 'perlbin' /etc/ /usr/

returns no results.

Last edited by N_BaH (2019-01-14 12:03:58)

ayekat

Member

Registered: 2011-01-17

Posts: 1,589

Re: [solved] bash PATH has extra paths

Have a look at /etc/profile. In particular, these lines:

# Load profiles from /etc/profile.d
if test -d /etc/profile.d/; then
        for profile in /etc/profile.d/*.sh; do
                test -r "$profile" && . "$profile"
        done
        unset profile
fi

This also explains why your grep there doesn't give any results.

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pkgs │ hacks │ cfg │ blag

N_BaH

Member

Registered: 2015-12-30

Posts: 84

Re: [solved] bash PATH has extra paths

of course!
thank you very much.

I've made some changes to the files so appendpath function can be applied into perlbin.sh

# diff /etc/profile{,.orig}
15c15,17
< export -f appendpath
---
> 
> unset appendpath
> 
29,30d30
< 
< unset appendpath

# diff /etc/profile.d/perlbin.sh{,.orig}
6,7c6,7
< [ -d /usr/bin/site_perl ] && appendpath /usr/bin/site_perl #PATH=$PATH:/usr/bin/site_perl
< [ -d /usr/lib/perl5/site_perl/bin ] && appendpath /usr/lib/perl5/site_perl/bin #PATH=$PATH:/usr/lib/perl5/site_perl/bin
---
> [ -d /usr/bin/site_perl ] && PATH=$PATH:/usr/bin/site_perl
> [ -d /usr/lib/perl5/site_perl/bin ] && PATH=$PATH:/usr/lib/perl5/site_perl/bin
9,10c9,10
< [ -d /usr/bin/vendor_perl ] && appendpath /usr/bin/vendor_perl #PATH=$PATH:/usr/bin/vendor_perl
< [ -d /usr/lib/perl5/vendor_perl/bin ] && appendpath /usr/lib/perl5/vendor_perl/bin #PATH=$PATH:/usr/lib/perl5/vendor_perl/bin
---
> [ -d /usr/bin/vendor_perl ] && PATH=$PATH:/usr/bin/vendor_perl
> [ -d /usr/lib/perl5/vendor_perl/bin ] && PATH=$PATH:/usr/lib/perl5/vendor_perl/bin
12c12
< [ -d /usr/bin/core_perl ] && appendpath /usr/bin/core_perl #PATH=$PATH:/usr/bin/core_perl
---
> [ -d /usr/bin/core_perl ] && PATH=$PATH:/usr/bin/core_perl

Last edited by N_BaH (2019-01-14 13:02:33)