I'm working on a bash function to check if a tmux session is running. The function works but if no session is running it outputs "failed to connect to server". How do I output that error to null without appending 1>&2 to every function call?
tmux_checker()
{
if [ -z $(tmux ls | grep -o servercontrol) ]
then
tmux new -d -s servercontrol
fi
}
tmux_checker #> /dev/null 2>&1 or 1>&2
Redirect the output in the function itself:
tmux_checker()
{
if [ -z $(tmux ls 2>/dev/null | grep -o servercontrol) ]
then
tmux new -d -s servercontrol
fi
}
tmux_checker
To test for an existing tmux session (and start a new one in the background if none exists), use
if ! tmux has-session 2>/dev/null; then
tmux new-session -d
fi
To check for a session with a specific name:
if ! tmux has-session -t name 2>/dev/null; then
tmux new-session -d -s name
fi
As a shell function:
start_tmux () {
set -- "${1:-servercontrol}"
if ! tmux has-session -t "$1" 2>/dev/null; then
tmux new-session -d -s "$1"
fi
}
This may be used as
$ start_tmux
or
$ start_tmux mysession
tmux_checkermultiple times in the script and didn't want to have to call it astmux_checker 2>&/dev/nulleach time.