How to count how many shell/terminals are running?

Question

I´m trying to count how many shell or terminal windows are currently running.

I tried ps a|grep bash; ps a|grep tty;

But it can be inaccurate.

Answer 1

ls /dev/pts/  | wc -l

Use the above command to count the terminal windows open.

Answer 2

To list them:

ps aux | awk '{print $7}' | grep -v "?"

To count them:

ps aux | awk '{print $7}' | grep -v "?" | wc -l

You will need to subtract 1 from that number as it includes the top TTY header.

This all depends if you are wanting to count how many sub shells are running or if you are wanting to count how many terminal windows are open.

To count just the terminal windows you would need to use:

ls /dev/pts/ | wc -l (stated in a previous answer)

For example:

On my system there are currently six tty's available. I also have one terminal open pts/0 that has 4 processes running in the fg or bg.

root      4565  0.0  0.0   4060   576 tty1     Ss+  May01   0:00 /sbin/mingetty /dev/tty1
root      4567  0.0  0.0   4060   572 tty2     Ss+  May01   0:00 /sbin/mingetty /dev/tty2
root      4569  0.0  0.0   4060   568 tty3     Ss+  May01   0:00 /sbin/mingetty /dev/tty3
root      4571  0.0  0.0   4060   576 tty4     Ss+  May01   0:00 /sbin/mingetty /dev/tty4
root      4573  0.0  0.0   4060   576 tty5     Ss+  May01   0:00 /sbin/mingetty /dev/tty5
root      4575  0.0  0.0   4060   572 tty6     Ss+  May01   0:00 /sbin/mingetty /dev/tty6

me  17482  0.0  0.0 110236  1136      pts/0    R+   11:36   0:00 ps aux
root     20374  0.0  0.0 108336  1816 pts/0    Ss   May23   0:00 -bash
root     20953  0.0  0.1 161436  1960 pts/0    S    May23   0:00 su - me
me  20954  0.0  0.1 108524  1984      pts/0    S    May23   0:00 -bash

If you want to take away the background child processes then just pipe to uniq:

ps aux | awk '{print $7}' | grep -v "?" | uniq | wc -l

You still have to subtract 1 for the header title of TTY, but you can further improve this by taking the tty's out altogether as it appears you don't care about those anyways.

ps aux | awk '{print $7}' | grep -v "?" | grep -vi "tty*" | uniq

That will give you an accurate count.

EDIT

Thinking about it more 'ps -a' would work better and you can leave out the first grep.

ps a | awk '{print $2}' | grep -vi "tty*" | uniq | wc -l

Answer 3

On macos you can use:

cnt=$(w -h | grep "^$(whoami) *s[^ ]* *-"|wc -l)
echo "Your current terminal sessions: $cnt"

Found here: https://stackoverflow.com/a/6180547/6320039

Answer 4

You could do $ pgrep bash

Also you can do $ W

Answer 5

You can add the \l option in your PS1 variable, example:

export PS1="terminal #\l \W \$ "

That will count your terminals starting from zero.

More about it in the GNU website.

Hope this helps.