Hi Alejandro,
Alejandro Colomar wrote on Tue, Aug 02, 2022 at 02:14:58PM +0200:
> I'd like to be able to produce ASCII HT ('\t' - horizontal tab) in man
> pages output. I don't want to align things; I do want a tab character.
> Rationale: examples in fstab(5).
I don't understand. On Debian, fstab(5) is part of the "mount"
package - which seems very reasonable to me - and it says:
Fields on each line are separated by tabs or spaces.
What's wrong with using spaces?
Wanting to show literal tab characters to users in a manual page
seems a dubious goal to me for two reasons:
* They are visually indistinguishable from spaces, so if the
distinction really matters, confusion is almost guaranteed to ensue.
* Some users may use pagers that convert tabs to spaces or vice
versa, so even if you hope for pastability, you still need
luck for it to work as intended.
> Is that possible? I didn't find anything in groff_char(7).
In groff, this works for me:
$ printf "a\\\\N'9'b" | groff -T ascii | hexdump -C | head -n 1
00000000 61 09 62 0a 0a 0a 0a 0a 0a 0a 0a 0a 0a 0a 0a 0a |a.b.............|
Mandoc behaves differently and treats \N'9' exactly like a literal HT:
$ printf "a\\\\N'9'b" | mandoc | hexdump -C | grep 61
00000050 61 20 20 20 20 62 0a 0a 20 20 20 20 20 20 20 20 |a b.. |
In general, mandoc lets fewer control characters sneak through into
output than groff because i worry that control characters in output
might occasionally cause reliability or security issues.
Yours,
Ingo
