Libguestfs - Sep 2019 - [PATCH nbdkit] docs: Suggest how to detect if a filter is installed.

Thanks: Eric Blake, Martin Kletzander.
---
 docs/nbdkit-probing.pod | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/docs/nbdkit-probing.pod b/docs/nbdkit-probing.pod
index 94bdfb4..46a7c47 100644
--- a/docs/nbdkit-probing.pod
+++ b/docs/nbdkit-probing.pod
@@ -80,6 +80,17 @@ installed.  A complete shell script which does this is:
      fi
  done
 
+=head2 Detect if a filter is installed
+
+To find out if a filter is installed (and working) use
+I<--dump-plugin> with the C<null> plugin and the name of the filter
to
+test:
+
+ nbdkit --dump-plugin --filter=foo null
+
+This will fail with an error and non-zero exit code if the C<foo>
+filter cannot be loaded.
+
 =head1 SEE ALSO
 
 L<nbdkit(1)>.
-- 
2.23.0

On Sat, Sep 21, 2019 at 03:53:45PM +0100, Richard W.M. Jones
wrote:
>Thanks: Eric Blake, Martin Kletzander.
>---
> docs/nbdkit-probing.pod | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
>diff --git a/docs/nbdkit-probing.pod b/docs/nbdkit-probing.pod
>index 94bdfb4..46a7c47 100644
>--- a/docs/nbdkit-probing.pod
>+++ b/docs/nbdkit-probing.pod
>@@ -80,6 +80,17 @@ installed.  A complete shell script which does this is:
>      fi
>  done
>
>+=head2 Detect if a filter is installed
>+
>+To find out if a filter is installed (and working) use
>+I<--dump-plugin> with the C<null> plugin and the name of the
filter to
>+test:
>+
>+ nbdkit --dump-plugin --filter=foo null
>+
>+This will fail with an error and non-zero exit code if the C<foo>
>+filter cannot be loaded.
>+
Looks good, for people like me it would be also nice to mention that the above
command will list the filter's parameters as well.

ACK
> =head1 SEE ALSO
>
> L<nbdkit(1)>.
>-- 
>2.23.0
>

On Sat, Sep 21, 2019 at 09:41:04PM +0200, Martin Kletzander
wrote:
> On Sat, Sep 21, 2019 at 03:53:45PM +0100, Richard W.M. Jones wrote:
> >Thanks: Eric Blake, Martin Kletzander.
> >---
> >docs/nbdkit-probing.pod | 11 +++++++++++
> >1 file changed, 11 insertions(+)
> >
> >diff --git a/docs/nbdkit-probing.pod b/docs/nbdkit-probing.pod
> >index 94bdfb4..46a7c47 100644
> >--- a/docs/nbdkit-probing.pod
> >+++ b/docs/nbdkit-probing.pod
> >@@ -80,6 +80,17 @@ installed.  A complete shell script which does this
is:
> >     fi
> > done
> >
> >+=head2 Detect if a filter is installed
> >+
> >+To find out if a filter is installed (and working) use
> >+I<--dump-plugin> with the C<null> plugin and the name of
the filter to
> >+test:
> >+
> >+ nbdkit --dump-plugin --filter=foo null
> >+
> >+This will fail with an error and non-zero exit code if the
C<foo>
> >+filter cannot be loaded.
> >+
>
> Looks good, for people like me it would be also nice to mention that
> the above command will list the filter's parameters as well.
Hehe, unfortunately it lists the plugin's parameters modulated by
the filter's parameters :-(  Another reason why we really
need a proper dump-filter mode, one day.

Thanks,

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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