detect active ttys regardless if a process is attached to any.

SCerovec · 01-19-2022, 07:07 PM

This was off topic in requests for -current, so far we had few attempts be a close match but no cigar.

here mine:

Code:

#!/bin/bash

ps ax | grep -e " tty" | grep -v "grep" | awk '{print $2}'

Hope the other gentlemen (and ladies) chime in...

The issue is - we want to detect the running tty regardless if it has a process attached to it.

GazL · 01-19-2022, 07:30 PM

Code:

active_ttys () 
{ 
    { 
        ps -Nd -o tty | grep tty[0-9];
        sed -n '/tty[0-9]/ { s/^\(tty[0-9]*\)\(.*\)/\1/ ; p }' /proc/consoles
    } | sort
}

Best I can come up with.

This will assume that there's a controlling process on each tty (except /dev/console): which should be the case, but might not be.

For using in a loop in rc.font though, I'm feeling it's over-engineered, and best just left to hard-coded values on the for, but it'd look something like this:

Code:

#!/bin/sh
#
# This selects your default screen font from among the ones in
# /usr/share/kbd/consolefonts.
#

font='ter-v24b'

active_ttys()
{ 
  { 
    ps -Nd -o tty | grep tty[0-9]
    sed -n '/tty[0-9]/ { s/^\(tty[0-9]*\)\(.*\)/\1/ ; p }' /proc/consoles 
  } | sort
}

for vc in $( active_ttys )
do
  setfont -C /dev/$vc "$font"
done

SCerovec · 01-19-2022, 07:34 PM

Did You account for TTY can be up to 63 there?

GazL · 01-19-2022, 07:49 PM

Yes, that should work. The only purpose of checking the first numeric char is to ensure that it doesn't match 'ttyS' devices.

GazL · 01-20-2022, 08:44 AM

Actually, there's still a problem with this. It works after boot, but at the point rc.M calls rc.font, the getty processes haven't been started.

So, back to my first idea of just hard-coding the names of the ttys I want to set the font on.

The other alternative of course, is to just put a setfont in /etc/profile so that it happens at login.

SCerovec · 01-20-2022, 05:55 PM

In fact the only place that decides where a login will run is inittab, right?

Where is the place the kernel console is pointed to a tty or serial port? Can we inhere that from dmesg?

GazL · 01-21-2022, 05:54 AM

Yes, the getty are started by inittab (unless its a systemd system of course). console is determined by console= kernel boot parameter.

I'm just going to KISS and hardcode 1-8 on the for loop and leave it at that.

baumei · 01-21-2022, 07:06 AM

If you "hardcode 1-8" into a for-loop in /etc/rc.d/rc.font, then I hope you also put a 'comment' into /etc/inittab for subsequent sys-admins about the gotcha lurking...

Quote:

Originally Posted by GazL

I'm just going to KISS and hardcode 1-8 on the for loop and leave it at that.

GazL · 01-21-2022, 07:46 AM

Whether a getty is running on it or not really isn't relevant here. What matters is which virtual consoles the admin/user wants the font applied to: which is handled by rc.font. So, no need for a comment in inittab; a comment in rc.font explaining should do the job.

JMGonk · 01-21-2022, 11:00 AM

My take on it, not sure if it satisfies all requirements:

Code:

for i in $(awk '$1 ~ /^c[0-9]+:1?[2345]+:respawn:[^:]*getty$/ {print $(NF-1)}' /etc/inittab); do ls -l /dev/$i; done

You can also do away with the for loop and just make a system() call from within awk:

Code:

awk '$1 ~ /^c[0-9]+:1?[2345]+:respawn:[^:]*getty$/ {system("ls -l /dev/"$(NF-1))}' /etc/inittab