Re: [Groff] Introduction

[Keith MARSHALL]

Werner Lemberg wrote:
>> In the case of SGR sequences, unless the user specifically uses
>> the `--enable-sgr' option, [...]
>
> Keith, maybe you've sent this as a private mail to David ...

Not intentionally.  Looks like I hit "Reply" instead of "Reply-to-All",
forgetting that groff list mailings don't set the "Reply-to" header
appropriately :-(  Could this be altered, as say, the SourceForge mail
lists do?

> (who has replied accidentally to the list)?  It looks interesting,
> so I ask you to send the full text to the list.

The full text of my original message is reproduced below.  (Note that
where I cite `--with-nroff="/path/to/nroff -Tlatin1"' for configuration
of man's default nroff command, that should have been

  --with-nroff="/path/to/nroff -Tlatin1 -mandoc"

).

------------------------------------

Quoting dialogue between David Evans and Werner Lemberg,
concerning the handling of SGR escape sequences in manpages:

[David]
> However, I think a better idea would be to do it through the
> configure script.  Did I overlook an option already present?

[Werner]
> What shall the *groff* configure script do?  Shouldn't this be rather
> something in the *man* configure script?

[David]
> The removal of the escape characters, etc., for a compatible output
> with OpenBSD's default, (this would be a configure option).  For
> now, I guess a simple note (to the INSTALL file) that man -R needs
> to be set globally to the system profile.

I agree with Werner;  this is a `man' configuration option, not one
for `groff'.

I am currently working on a port of `man' for the MinGW project.  As
a fundamental part of that port, I've opted for a reimplementation of
the configure script, from the ground up, using `autoconf';  (the
existing script is hand crafted, falls into many of the traps that
`autoconf' has long ago learned to avoid, and is, quite frankly, a
complete disaster on the Win32 platform).

When `man' is invoked, a search is performed in the `man' directories,
and then a command pipeline, culminating in `nroff <options> | $PAGER',
is constructed, and invoked via a `system()' call.  It's those options
passed by `man' to `nroff', coupled with any also specified for the
PAGER, that determine the handling of SGR escape sequences, so it
doesn't seem appropriate to try to control them when configuring
`groff'.

As part of the `man' configuration, the commands to run both `nroff'
and a default PAGER, together with the appropriate set of options for
each, are identified, and stored in a prototype `man.conf'.  In my new
configure script, I provide options such as `--with-nroff=command',
`--with-pager=command' and `--enable-sgr', to allow the user to
control the configuration of these;  my defaults are:--

   --with-nroff="/path/to/nroff -Tlatin1"
   --with-pager="/path/to/less -is"
   --disable-sgr

with the `/path/to/programs' being determined by standard `autoconf'
PATH searches.

In the case of SGR sequences, unless the user specifically uses the
`--enable-sgr' option, `configure' will attempt to run the specified
`nroff' command, to format a minimal manpage, and `grep' the output for
an identifiable SGR sequence, before adding the `-c' option to the
configured `nroff' command.

As noted above, all this configuration info goes in the `man.conf' file.
This may be modified, even after installation, to adjust the behaviour
of `man';  `groff' documentation indicates how it may be necessary to
adjust the settings in `man.conf', and also identifies alternative
mechanisms for achieving similar effects, through environment variable
settings.  IMHO, this is as far as `groff' should be expected to go,
in this respect.

Regards,
Keith.