Red Hat Bugzilla – Bug 202468
less breaks if its startup script outputs anything
Last modified: 2015-03-04 20:17:23 EST
Description of problem:
This was initially raised by Jack Neely (firstname.lastname@example.org, see bz #186931,
comment #3) and verified to be present in RHEL 4.4
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Create /etc/profile.d/test.csh that contains:
2.Login as a user with tcsh as the default shell
3.Run: less /etc/hosts
You see the word "FOO" displayed rather than the text of /etc/hosts
the text of /etc/hosts
less does a popen("/bin/tcsh -c /usr/bin/lesspipe.sh /etc/hosts") where
the shell is gotten from the users default shell.
This is caused by a processing of scripts /etc/profile.d/* in non-interactive
mod of tcsh. When tcsh is executed, then all scripts in /etc/profile.d/*.csh are
executed too. Even in non-interactive mod. But in this mod, tcsh should not
execute those scripts. This bad behavior leads to problems, because a less is
confused. Then the less accepts as a input a text from echo instead a text from
/etc/hosts. The solution is to reflect non-interactive mod in /etc/csh.cshrc.
I'll attach a patch, which solve this.
Created attachment 265921 [details]
patch to fix non-interactive mod of tcsh
Very simple fix, proposing for RHEL-4.8 FasTrack.
Read ya, Phil
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.
This fix caused regression - bug #464788. In my opinion fix should be reverted because it is impossible fix both #202468 and #464788.
Created attachment 322565 [details]
Patch to fix non-interactive mod of tcsh (and keep path definition processing)
I guess both issues could be solved together by redirecting stdout and stderr to /dev/null for noninteractive shells ... tried following patch and it works for me in both cases.