exists

cyber-mux exists <pane>

Probe whether a single pane is still live. Prints live or gone. Exits 0 when live, 1 when gone — resolution runs before any output, so an ambiguous locator throws instead of printing either word for a question that has no single pane to be about.

<pane> takes either a pane id or a label — see Pane for resolution rules.

Examples

cyber-mux exists %3
# live

# Wait for a pane to close
while cyber-mux exists %3 > /dev/null; do sleep 1; done