Bug 2025709 - /etc/profile.d/which2.sh incorrectly tests for ksh (and mksh, zsh) shells [NEEDINFO]
Summary: /etc/profile.d/which2.sh incorrectly tests for ksh (and mksh, zsh) shells
Alias: None
Deadline: 2022-01-10
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: which
Version: 8.5
Hardware: Unspecified
OS: Linux
Target Milestone: rc
: 8.6
Assignee: Than Ngo
QA Contact: Jakub Haruda
: 2060919 (view as bug list)
Depends On:
TreeView+ depends on / blocked
Reported: 2021-11-22 19:26 UTC by tc.staff
Modified: 2022-09-21 16:32 UTC (History)
11 users (show)

Fixed In Version: which-2.21-17.el8
Doc Type: No Doc Update
Doc Text:
Clone Of:
Last Closed: 2022-05-10 15:25:05 UTC
Type: Bug
Target Upstream Version:
than: needinfo? (ccheney)

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker RHELPLAN-103597 0 None None None 2021-11-22 19:28:53 UTC
Red Hat Product Errata RHBA-2022:2067 0 None None None 2022-05-10 15:25:08 UTC

Description tc.staff 2021-11-22 19:26:02 UTC
Description of problem:

/etc/profile.d/which2.sh incorrectly tests for ksh (and mksh, zsh) shells, sets 'declare -f' instead of 'typeset -f'

Version-Release number of selected component (if applicable):


How reproducible:

Steps to Reproduce:
1. create a ksh script that uses #!/usr/bin/ksh
2. run script via cron

Actual results:

When the profiles get run you see

export: -f: unknown option

Expected results:

run script without trying to 'declare -f' in the which2.sh profile

Additional info:

The problem is here -

which_shell="$(cat /proc/$$/comm)"

if [ "$which_shell" = "ksh" ] || [ "$which_shell" = "mksh" ] || [ "$which_shell" = "zsh" ] ; then
  which_declare="typeset -f"


/proc/$$/comm is the name of the command. If the script is "test.ksh" and called
directly it of course doesn't detect a ksh shell, it thinks the shell is "test.ksh".

Is kind of amazing how this passed automated tests? Maybe need to be some new tests.

Comment 4 tc.staff 2021-11-23 20:19:38 UTC
A quick point of clarification: this isn't really cron related. If the script is passed to the interpreter (ksh <script>) then /etc/profile.d/which2.sh will behave as intended. However, if the script is marked as executable and invoked directly (./script) then /proc/$$/comm will contain the name of the script.

$ cat test.ksh
cat /proc/$$/comm

$ ./test.ksh

$ ksh test.ksh


Comment 5 Than Ngo 2021-11-23 21:08:09 UTC
sadly i cannot reproduce your reported issue. It will help me a lot if you can provide working reproduce.


Comment 6 tc.staff 2021-11-23 21:15:24 UTC
You bet! 

The steps are below, including reinstalling which (our configuration management automatically replaces the file when it runs).

You'll need to source /etc/profile to invoke /etc/profile.d/which2.sh. You'd do this for non-interactive shells including cron tasks and cluster jobs in certain cases. For example, we use Lmod which requires setup via /etc/profile.d/ files.

Let me know if this helps and if you need any other info.

[jstroik@c8test ~]$ sudo dnf reinstall which
Duo two-factor login for jstroik



[jstroik@c8test ~]$ vim test.ksh
[jstroik@c8test ~]$ chmod +x test.ksh
[jstroik@c8test ~]$ cat test.ksh
echo "about to source /etc/profile"
source /etc/profile
echo "Sourced /etc/profile"

[jstroik@c8test ~]$ ./test.ksh
about to source /etc/profile
./test.ksh[3]: .[70]: .[19]: export: -f: unknown option
Usage: export [-p] [name[=value]...]
Sourced /etc/profile

Comment 7 Than Ngo 2021-11-25 14:56:53 UTC
thanks for the test, i can now reproduce this issue with above steps.
Could you please download https://than.fedorapeople.org/rhel8/which/which-2.21-17.el8.x86_64.rpm and test?


Comment 9 tc.staff 2021-11-26 22:35:26 UTC
Yes - I confirm I no longer receive the error. Thank you.

Looking at the updated which2.sh if you have an example script like this:

source /etc/profile
cat /proc/$$/comm
eval ${which_declare}

You will get different results if you ./test.zsh vs 'zsh test.zsh' due to the way /proc/$$/comm resolves.

Comment 19 Welterlen Benoit 2022-03-21 14:18:07 UTC
*** Bug 2060919 has been marked as a duplicate of this bug. ***

Comment 21 errata-xmlrpc 2022-05-10 15:25:05 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (which bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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