Re: [PATCH v3] cpupower: Make help command available for custom install dir

[Shuah Khan <skhan@linuxfoundation.org>]

On 7/2/24 01:40, Roman Storozhenko wrote:
> On Mon, Jul 1, 2024 at 9:40 PM Shuah Khan <skhan@linuxfoundation.org> wrote:
>>
>> On 6/29/24 04:48, Roman Storozhenko wrote:
>>> On Fri, Jun 28, 2024 at 9:45 PM Shuah Khan <skhan@linuxfoundation.org> wrote:
>>>>
>>>> On 6/28/24 05:30, Roman Storozhenko wrote:
>>>>> On Thu, Jun 27, 2024 at 7:33 PM Shuah Khan <skhan@linuxfoundation.org> wrote:
>>>>>>
>>>>>> On 6/27/24 01:49, Roman Storozhenko wrote:
>>>>>>> When the 'cpupower' utility installed in the custom dir, it fails to
>>>>>>> render appropriate help info for a particular subcommand:
>>>>>>> $ LD_LIBRARY_PATH=lib64/ bin/cpupower help monitor
>>>>>>> with error message like 'No manual entry for cpupower-monitor.1'
>>>>>>> The issue is that under the hood it calls 'exec' function with
>>>>>>> the following args: 'man cpupower-monitor.1'. In turn, 'man' search
>>>>>>> path is defined in '/etc/manpath.config'. Of course it contains only
>>>>>>> standard system man paths.
>>>>>>> Make subcommands help available for a user by setting up 'MANPATH'
>>>>>>> environment variable to the custom installation man pages dir. That
>>>>>>> variable value will be prepended to the man pages standard search paths
>>>>>>> as described in 'SEARCH PATH' section of MANPATH(5).
>>>>>>
>>>>>> What I am asking you is what happens when you set the MANPATH before
>>>>>> running the command?
>>>>>
>>>>> It adds the custom search path to the beginning of the MANPATH variable.
>>>>> I tested this case. All works as expected.
>>>>>
>>>>
>>>> Let's try again. What happens if you run the command with MANPATH set and
>>>> exported and then run the command. Can you send the output?
>>>
>>> hedin@laptop:~/prj/cpupower/install/usr$ echo $MANPATH
>>> /tmp/
>>> hedin@laptop:~/prj/cpupower/install/usr$ LD_LIBRARY_PATH=lib64/
>>> bin/cpupower help monitor
>>> ...................
>>> man output
>>> ...................
>>> hedin@laptop:~/prj/cpupower/install/usr$ echo $MANPATH
>>> /tmp/
>>> hedin@laptop:~/prj/cpupower/install/usr$
>>>
>>
>> Is this with your patch or mainline? Can you give cut and paste
>> the man output here for the mainline coupower without your patch?
> 
> The above output is from my patch.
> This is the output from the mainline:
> hedin@laptop:~/prj/cpupower/install/usr$ sudo LD_LIBRARY_PATH=lib64/
> bin/cpupower help monitor
> [sudo] password for hedin:
> No manual entry for cpupower-monitor
> hedin@laptop:~/prj/cpupower/install/usr$ echo $MANPATH
> /tmp/

Why is MANPATH set to /tmp?

> hedin@laptop:~/prj/cpupower/install/usr$
> 

Okay. If you run the command as follows and get the man page for
it, then I don't see a reason to add code to make it happen.

sudo MANPATH=$MANPATH:path_to_custom_install_man_dir LD_LIBRARY_PATH=lib64/ bin/cpupower help monitor

thanks,
-- Shuah