AW: .ad l/.ad b

From: Oliver Corff <oliver.corff@email.de>
To: "Alejandro Colomar (man-pages)" <alx.manpages@gmail.com>,
	"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>,
	"G. Branden Robinson" <g.branden.robinson@gmail.com>
Cc: linux-man <linux-man@vger.kernel.org>, groff@gnu.org
Subject: AW: .ad l/.ad b
Date: Sun, 12 Sep 2021 13:33:38 +0200	[thread overview]
Message-ID: <20210912113338.5181521.88860.87504@email.de> (raw)
In-Reply-To: <d95326e0-7b0c-b057-3412-f60264fe1ad9@gmail.com>

Hi,

.ad Begin line adjustment for output lines in current
adjust mode.
.ad c Start line adjustment in mode c (c=l,r,c,b,n).

That looks like left, right, centered, block and neutral?

Just my uninformed guess, and I am not at all sure about my impromptu Interpretation of 'n'.

Best regards, 
Oliver.

Dr. Oliver Corff‎
Mailto:oliver.corff@email.de
  Originalnachricht  
Von: Alejandro Colomar (man-pages)
Gesendet: Sonntag, 12. September 2021 13:13
An: Michael Kerrisk (man-pages); G. Branden Robinson
Cc: linux-man; groff@gnu.org
Betreff: .ad l/.ad b

Hi, Branden and Michael!

I've seen these in shmctl.2, and didn't know what they mean.
groff(7) wasn't very helpful.

[
.SH SYNOPSIS
.nf
.ad l
.B #include <sys/shm.h>
.PP
.BI "int shmctl(int " shmid ", int " cmd ", struct shmid_ds *" buf );
.ad b
.fi
]

What are those '.ad X' and do we really need them?

I found some other pages that use it:

[
.../linux/man-pages$ grep -rn '^\.ad b' man?
man1/localedef.1:60:.ad b
man2/setsid.2:40:.ad b
man2/acct.2:41:.ad b
man2/shmctl.2:55:.ad b
man2/shmget.2:50:.ad b
]

groff(7) related info:

[
.ad Begin line adjustment for output lines in current
adjust mode.
.ad c Start line adjustment in mode c (c=l,r,c,b,n).
]

But what does each mode mean? I couldn't find anything about them in 
the manual page.

Thanks,

Alex

-- 
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/