Bug 50241

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User-Agent: Mozilla/4.75 [en] (X11; U; Linux 2.2.16-22 i686)

Description of problem:
When an initscript starts with ``#!/bin/bash'' it may well involve user
customizations
(e.g. via $BASH_ENV).  Bash has an option ("set -u" or "set -o nounset")
which
causes the shell to treat unset variables as an error.  This can cause init
scripts to
fail for some users.  You can make "functions" more robust by replacing
lines like
this: ``[ -z "$COLUMNS" ] && COLUMNS=80''
with lines like this: ``${COLUMNS:=80}''

The effect should be the same, and would allow those of us who like to use
bash with
the "nounset" option to keep doing so without tripping over init script
failures.  Some
such init scripts are atd, gpm, halt, netfs and sshd.


How reproducible:
Always

Steps to Reproduce:
1. log in as root
2. append "set -o nounset" to ~/.bashrc
3. try `/etc/init.d/sshd status`


Actual Results:  The sshd init script bombed out (exit value 1) with:

  /etc/init.d/sshd: COLUMNS: unbound variable

That error comes from the following line in "functions", which is
dot-sourced by the
sshd init script:

  [ -z "$COLUMNS" ] && COLUMNS=80


Expected Results:  The sshd init script should have told me the status of
the sshd service,
rather than exiting with a non-zero value.


Additional info:

My first thought was that init scripts should stick to /bin/sh rather than
/bin/bash,
but concluded that "functions" is the appropriate place for the fix.  Init
scripts have
valid reasons to use bash functions instead of minimal sh capabilities, and
there
will always be people you don't know about writing init scripts.