New: Environment variable MANLESS is described wrong in man(1)

https://bugzilla.kernel.org/show_bug.cgi?id=216603

             Bug ID: 216603
            Summary: Environment variable MANLESS is described wrong in
                     man(1)
            Product: Documentation
            Version: unspecified
           Hardware: All
                 OS: Linux
             Status: NEW
           Severity: normal
           Priority: P1
          Component: man-pages
           Assignee: [email protected]
           Reporter: [email protected]
         Regression: No

In an example for setting MANLESS environment variable, man(1) claims:

For example, if you want to set the prompt string unconditionally to "my prompt string", set $MANLESS to '-Psmy prompt string'.

However, this is not not correct as man uses the entire MANLESS variable as a prompt for less. I'll demonstrate:

     $ MANLESS='-Ps(prompt)' man man
     <ctrl-z>
     $ cat /proc/$(pgrep -P $(pgrep -f "man man"))/environ |
     tr '\0' '\n' | grep "^LESS="

     LESS=-ix8RmPm-Ps(prompt)$PM-Ps(prompt)$

As seen, man(1) defines -Pm and -PM prompts using the MANLESS variable as is. The same applies to the command line option -r:

     $ man -r'-Ps(prompt)' man
     <ctrl-z>
     $ cat /proc/$(pgrep -P $(pgrep -f "man .* man"))/environ |
     tr '\0' '\n' | grep "^LESS="

     LESS=-ix8RmPm-Ps(prompt)$PM-Ps(prompt)$

Option -r does not make the same claim, but it says:

By default man sets the -ix8 options.

Which also is a bit outdated as we can see it sets -ix8R.

So in summary, at least the '-Ps' part should be removed from the MANLESS description example. Furthermore, option -r description could elaborate on how LESS variable is formed (-ix8RmPm<MANLESS or -r>$PM<MANLESS or -r>$).

Note: Dollar sign in less prompt definition is an end-of-string marker.

Hi Arttu,

Quoted 25 lines · On 10/18/22 21:55, [email protected] wrote:

https://bugzilla.kernel.org/show_bug.cgi?id=216603

             Bug ID: 216603
            Summary: Environment variable MANLESS is described wrong in
                     man(1)
            Product: Documentation
            Version: unspecified
           Hardware: All
                 OS: Linux
             Status: NEW
           Severity: normal
           Priority: P1
          Component: man-pages
           Assignee: [email protected]
           Reporter: [email protected]
         Regression: No

In an example for setting MANLESS environment variable, man(1) claims:

For example, if you want to set the prompt string unconditionally to "my prompt string", set $MANLESS to '-Psmy prompt string'.

However, this is not not correct as man uses the entire MANLESS variable as a prompt for less. I'll demonstrate:

Quoted 8 lines

     $ MANLESS='-Ps(prompt)' man man
     <ctrl-z>
     $ cat /proc/$(pgrep -P $(pgrep -f "man man"))/environ |
     tr '\0' '\n' | grep "^LESS="

     LESS=-ix8RmPm-Ps(prompt)$PM-Ps(prompt)$

As seen, man(1) defines -Pm and -PM prompts using the MANLESS variable

as is.

Quoted 9 lines

The same applies to the command line option -r:

     $ man -r'-Ps(prompt)' man
     <ctrl-z>
     $ cat /proc/$(pgrep -P $(pgrep -f "man .* man"))/environ |
     tr '\0' '\n' | grep "^LESS="

     LESS=-ix8RmPm-Ps(prompt)$PM-Ps(prompt)$

Quoted 8 lines

Option -r does not make the same claim, but it says:

By default man sets the -ix8 options.

Which also is a bit outdated as we can see it sets -ix8R.

So in summary, at least the '-Ps' part should be removed from the MANLESS description example. Furthermore, option -r description could elaborate

on

Quoted 4 lines

how LESS variable is formed (-ix8RmPm<MANLESS or -r>$PM<MANLESS or -r>$).

Note: Dollar sign in less prompt definition is an end-of-string marker.

The man(1) page is part of the man-db project, not the Linux man-pages. Colin is the maintainer of man-db, so I CCd him.

Their website is:

<https://man-db.nongnu.org/>

However, I'm curious about the resolution, so if you report it again in the man-db bug tracker (I guess that's their gitlab? don't remember), please CC me. :)

Cheers,

Alex

--
<http://www.alejandro-colomar.es/>