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From: Magnus Hagander <magnus@hagander.net>
Date: Mon, 8 Nov 2021 10:03:50 +0100
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 <CABUevEz5X8qSCNEveNOU19Gy3FcOXdRgpP=Z33KUbDw=DNs_cA@mail.gmail.com>
Subject: Re: [PATCH] Improve portability of pgweb/load_initial_data.sh
To: Nils <nils@nilsand.re>
Cc: pgsql-www@lists.postgresql.org
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Hi!

Yeah, I think the fact that it says bash is just a "knee-jerk default" and
not that it ever did either. So I have no problem changing that to sh. I'm
a bit curious though, as to in which scenario this actually causes a
problem?

The second change I'm less sure about. There are many different things you
could change to break a script. This is one of them. You could change PATH,
or you could replace "find" or "xargs" with commands that don't work the
same way. CDPATH is not a variable that should, I believe, ever be exported
into non-interactive scripts in the first place.

//Magnus

On Sun, Nov 7, 2021 at 5:49 PM Nils <nils@nilsand.re> wrote:

> The shell script doesn't use bash extensions and bash may not be
> available on all systems at that location.
>
> If CDPATH is set, in certain cases, the call to cd can result in
> unwanted behaviour.
> ---
>  pgweb/load_initial_data.sh | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/pgweb/load_initial_data.sh b/pgweb/load_initial_data.sh
> index fb16e70c..c419f298 100755
> --- a/pgweb/load_initial_data.sh
> +++ b/pgweb/load_initial_data.sh
> @@ -1,4 +1,4 @@
> -#!/bin/bash
> +#!/bin/sh
>
>  # We keep this in a separate script because using initial_data.xxx in
> django will overwrite
>  # critical data in the database when running a 'syncdb'. We'd like to
> keep the ability to
> @@ -8,7 +8,7 @@ echo WARNING: this may overwrite some data in the database
> with an initial set o
>  echo 'Are you sure you want this (answer "yes" to overwrite)'
>  read R
>
> -cd $(dirname $0)
> +CDPATH= cd $(dirname $0)
>
>  if [ "$R" == "yes" ]; then
>     find . -name data.json | xargs ../manage.py loaddata
> --
> 2.31.1
>
>
>
>

-- 
 Magnus Hagander
 Me: https://www.hagander.net/ <http://www.hagander.net/>
 Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>

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<div dir=3D"ltr"><div>Hi!</div><div><br></div><div>Yeah, I think the fact t=
hat it says bash is just a &quot;knee-jerk default&quot; and not that it ev=
er did either. So I have no problem changing that to sh. I&#39;m a bit curi=
ous though, as to in which scenario this actually causes a problem?</div><d=
iv><br></div><div>The second change I&#39;m less sure about. There are many=
 different things you could change to break a script. This is one of them. =
You could change PATH, or you could replace &quot;find&quot; or &quot;xargs=
&quot; with commands that don&#39;t work the same way. CDPATH is not a vari=
able that should, I believe, ever be exported into non-interactive scripts =
in the first place.</div><div><br></div><div>//Magnus</div><br><div class=
=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Sun, Nov 7, 2021 =
at 5:49 PM Nils &lt;<a href=3D"mailto:nils@nilsand.re">nils@nilsand.re</a>&=
gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0=
px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">The s=
hell script doesn&#39;t use bash extensions and bash may not be<br>
available on all systems at that location.<br>
<br>
If CDPATH is set, in certain cases, the call to cd can result in<br>
unwanted behaviour.<br>
---<br>
=C2=A0pgweb/load_initial_data.sh | 4 ++--<br>
=C2=A01 file changed, 2 insertions(+), 2 deletions(-)<br>
<br>
diff --git a/pgweb/load_initial_data.sh b/pgweb/load_initial_data.sh<br>
index fb16e70c..c419f298 100755<br>
--- a/pgweb/load_initial_data.sh<br>
+++ b/pgweb/load_initial_data.sh<br>
@@ -1,4 +1,4 @@<br>
-#!/bin/bash<br>
+#!/bin/sh<br>
<br>
=C2=A0# We keep this in a separate script because using initial_data.xxx in=
 django will overwrite<br>
=C2=A0# critical data in the database when running a &#39;syncdb&#39;. We&#=
39;d like to keep the ability to<br>
@@ -8,7 +8,7 @@ echo WARNING: this may overwrite some data in the database =
with an initial set o<br>
=C2=A0echo &#39;Are you sure you want this (answer &quot;yes&quot; to overw=
rite)&#39;<br>
=C2=A0read R<br>
<br>
-cd $(dirname $0)<br>
+CDPATH=3D cd $(dirname $0)<br>
<br>
=C2=A0if [ &quot;$R&quot; =3D=3D &quot;yes&quot; ]; then<br>
=C2=A0 =C2=A0 find . -name data.json | xargs ../manage.py loaddata<br>
-- <br>
2.31.1<br>
<br>
<br>
<br>
</blockquote></div><br clear=3D"all"><div><br></div>-- <br><div dir=3D"ltr"=
 class=3D"gmail_signature"><div dir=3D"ltr"><div>=C2=A0Magnus Hagander<br>=
=C2=A0Me: <a href=3D"http://www.hagander.net/" target=3D"_blank">https://ww=
w.hagander.net/</a><br>=C2=A0Work: <a href=3D"http://www.redpill-linpro.com=
/" target=3D"_blank">https://www.redpill-linpro.com/</a></div></div></div><=
/div>

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