Libguestfs - Aug 2018 - Re: [PATCH nbdkit 08/10] freebsd: In scripts use 'env bash' instead of '/bin/bash'.

On 08/12/2018 03:51 AM, Richard W.M. Jones wrote:
> The path to bash on FreeBSD is /usr/local/bin/bash.
> ---
> +++ b/docs/make-links.sh
> @@ -1,4 +1,4 @@
> -#!/bin/bash -
> +#!/usr/bin/env bash
This loses the '-' argument that used to be passed by the kernel (but 
you can't add it back to the #! linew without using BSD's or GNU 
coreutils' recent addition of 'env -S').  Is it worth adding a
'set -'
line later in the script to compensate, if you were previously passing 
the '-' as a way to reset the shell from inheriting environmental 
differences?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

On Mon, Aug 13, 2018 at 04:14:13PM -0500, Eric Blake
wrote:
> On 08/12/2018 03:51 AM, Richard W.M. Jones wrote:
> >The path to bash on FreeBSD is /usr/local/bin/bash.
> >---
> 
> >+++ b/docs/make-links.sh
> >@@ -1,4 +1,4 @@
> >-#!/bin/bash -
> >+#!/usr/bin/env bash
> 
> This loses the '-' argument that used to be passed by the kernel
> (but you can't add it back to the #! linew without using BSD's or
> GNU coreutils' recent addition of 'env -S').  Is it worth
adding a
> 'set -' line later in the script to compensate, if you were
> previously passing the '-' as a way to reset the shell from
> inheriting environmental differences?
I actually had no idea what the '-' did until now :-)

I guess we need it.  I can add

  set -

to these scripts as required.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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On 08/13/2018 04:23 PM, Richard W.M. Jones wrote:
> On Mon, Aug 13, 2018 at 04:14:13PM -0500, Eric Blake wrote:
>> On 08/12/2018 03:51 AM, Richard W.M. Jones wrote:
>>> The path to bash on FreeBSD is /usr/local/bin/bash.
>>> ---
>>
>>> +++ b/docs/make-links.sh
>>> @@ -1,4 +1,4 @@
>>> -#!/bin/bash -
>>> +#!/usr/bin/env bash
>>
>> This loses the '-' argument that used to be passed by the
kernel
>> (but you can't add it back to the #! linew without using BSD's
or
>> GNU coreutils' recent addition of 'env -S').  Is it worth
adding a
>> 'set -' line later in the script to compensate, if you were
>> previously passing the '-' as a way to reset the shell from
>> inheriting environmental differences?
> 
> I actually had no idea what the '-' did until now :-)
Actually, I'm not sure if it does anything. 'set -u' isn't
inherited
across a #! setup, and I doubt anything else that 'set' controls would 
have an effect either (or people would have complained long before now 
on scripts that just do '#!/bin/bash' instead of '#!/bin/bash
-').
> 
> I guess we need it.  I can add
> 
>    set -
> 
> to these scripts as required.
Only if it makes a difference that you can actually observe in testing - 
don't bother to do it otherwise.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org