Re: [PATCH 2/2] copy-firmware: fail gracefully if moreutils parallel is installed

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hi Timur,

Timur Tabi <ttabi@nvidia.com> writes:

> On Tue, 2025-03-18 at 15:42 +0900, Maxim Cournoyer wrote:
>> I just rechecked; I don't think this currently work, it'd require
>> complicating the script to accommodate this less featureful parallel
>> variant, which is why I had opted to use GNU Parallel in the first place
>> :-).
>
> Like I said in my other reply, I think you misunderstood the point of my
> patch.  moreutils' parallel is still not supported.  I'm not trying to make it
> work.  All my patch does is make the function run more cleanly.  That's why I
> said "fail gracefully".

I see; I had indeed missed the point of your patch.  I understand the
problem this attempts to solve now, thanks for the clarifications.

+        # The moreutils package comes with a simpler version of "parallel"
+        # that does not support the --version or -a options.  Check for
+        # that first.  In some distros, installing the "parallel" package
+        # will replace the moreutils version with the GNU version.
+        parallel --version >/dev/null 2>&1
+        if [ $? -ne 0 ]; then
+            return 1
+        fi

Instead of checking $?, it's better style to check the command directly
like:

--8<---------------cut here---------------start------------->8---
@@ -22,8 +22,11 @@ warn() {
 
 has_gnu_parallel() {
     if command -v parallel > /dev/null; then
-        if parallel --version | grep -Fqi 'gnu parallel'; then
-           return 0
+        # Moreutils's parallel doesn't support '--version'.
+        if ! parallel --version >/dev/null 2>&1; then
+            return 1
+        elif parallel --version | grep -Fqi 'gnu parallel'; then
+            return 0
         fi
     fi
     return 1
--8<---------------cut here---------------end--------------->8---

-- 
Thanks,
Maxim