Libguestfs - Sep 2018 - Re: [PATCH nbdkit 1/4] build: Move list of plugins and filters to the configure script.

On 9/11/18 1:47 PM, Richard W.M. Jones wrote:
> It's easier to get it to other places if it starts out in the
> configure script.
> 
> Also split the list into language and non-language plugins.
> ---
>   common-rules.mk | 44 ----------------------------------------
>   configure.ac    | 53 +++++++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 53 insertions(+), 44 deletions(-)
> 
> +++ b/configure.ac
> @@ -542,6 +542,59 @@ AC_ARG_ENABLE([vddk],[
>       [enable_vddk=yes])
>   AM_CONDITIONAL([HAVE_VDDK], [test "x$enable_vddk" =
"xyes"])
>   
> +dnl List of plugins and filters.
> +lang_plugins="\
> +        lua \
> +        ocaml \
> +        perl \
> +        python \
> +        ruby \
> +        sh \
> +        tcl \
> +        "
> +non_lang_plugins="\
> +        curl \
> +        data \
> +	example1 \
> +	example2 \
Inconsistent spacing (space-vs-tab doesn't matter in this particular 
context, but it looks weird to use both)
> +        "
> +plugins="$(echo $lang_plugins $non_lang_plugins | xargs -n1 | sort -u
| xargs)"
Your use of xargs as a reformatter is interesting ;) Could also be spelled:

$(echo $lang_plugins $non_lang_plugins | tr -s ' \t\n' ' ' |
sort -u |
tr ' ' '\n')"

but that's longer to type, so your version is fine.

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

On Tue, Sep 11, 2018 at 02:13:03PM -0500, Eric Blake
wrote:
> On 9/11/18 1:47 PM, Richard W.M. Jones wrote:
> >It's easier to get it to other places if it starts out in the
> >configure script.
> >
> >Also split the list into language and non-language plugins.
> >---
> >  common-rules.mk | 44 ----------------------------------------
> >  configure.ac    | 53
+++++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 53 insertions(+), 44 deletions(-)
> >
> 
> >+++ b/configure.ac
> >@@ -542,6 +542,59 @@ AC_ARG_ENABLE([vddk],[
> >      [enable_vddk=yes])
> >  AM_CONDITIONAL([HAVE_VDDK], [test "x$enable_vddk" =
"xyes"])
> >+dnl List of plugins and filters.
> >+lang_plugins="\
> >+        lua \
> >+        ocaml \
> >+        perl \
> >+        python \
> >+        ruby \
> >+        sh \
> >+        tcl \
> >+        "
> >+non_lang_plugins="\
> >+        curl \
> >+        data \
> >+	example1 \
> >+	example2 \
> 
> Inconsistent spacing (space-vs-tab doesn't matter in this particular
> context, but it looks weird to use both)
Ooops.  Wasn't visible in emacs, but I can fix that next time.
> >+        "
> >+plugins="$(echo $lang_plugins $non_lang_plugins | xargs -n1 |
sort -u | xargs)"
> 
> Your use of xargs as a reformatter is interesting ;) Could also be spelled:
> 
> $(echo $lang_plugins $non_lang_plugins | tr -s ' \t\n' ' '
| sort -u
> | tr ' ' '\n')"
> 
> but that's longer to type, so your version is fine.
This one actually came from stackoverflow:

  https://stackoverflow.com/a/8802788

I wanted something that would work on BSD (although I didn't test it
yet ...)

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

On 9/11/18 4:06 PM, Richard W.M. Jones wrote:
>>> +        "
>>> +plugins="$(echo $lang_plugins $non_lang_plugins | xargs -n1 |
sort -u | xargs)"
>>
>> Your use of xargs as a reformatter is interesting ;) Could also be
spelled:
>>
>> $(echo $lang_plugins $non_lang_plugins | tr -s ' \t\n' '
' | sort -u
>> | tr ' ' '\n')"
>>
>> but that's longer to type, so your version is fine.
> 
> This one actually came from stackoverflow:
> 
>    https://stackoverflow.com/a/8802788
which also mentioned:

plugins=$(echo $(printf %s\\n $lang_plugins $non_lang_plugins | sort -u))

for less typing, fewer processes, and no dependence on xargs.

Isn't shell golf fun :)
> 
> I wanted something that would work on BSD (although I didn't test it
> yet ...)
I haven't tested on BSD either, but all of the solutions listed here 
[whether xargs, tr, or $echo $(printf %s\\n)] are portable at least 
according to POSIX.

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