tmux-send

#!/usr/bin/env bash
# Send text + Enter to a tmux target.
# Usage: tmux-send [--no-prefix] <target> <text...>
# Uses set-buffer/paste-buffer for reliable multi-line delivery; named buffer avoids concurrent-send collisions.
# NOTE: sending while an agent is mid-run (still processing) may cause odd behaviour — not fully tested.

PREFIX_MODE=1
if [ "${1:-}" = "--no-prefix" ]; then
    PREFIX_MODE=0
    shift
fi

if [ -z "${1:-}" ] || [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
    echo "Usage: tmux-send [--no-prefix] <target> <text...>"
    echo ""
    echo "Send literal text plus Enter to a tmux pane."
    echo ""
    echo "Arguments:"
    echo "  --no-prefix  Do not prepend sender identity when called from inside tmux"
    echo "  target       tmux session, window, or pane target"
    echo "           Examples: mysession, mysession:0, mysession:0.0"
    echo "           Bare session names default to :0.0"
    echo "  text     Text to send (joined with spaces)"
    echo ""
    echo "Examples:"
    echo "  tmux-send claude_myproject 'Hello agent'"
    echo "  tmux-send myproject:0.1 'ls -la'"
    exit 0
fi

TARGET="$1"
# Default to :0.0 (First window, first pane) if no pane specified in target string
if [[ "$TARGET" != *:*.* ]]; then
    # If target is just a session name (no colon), append :0.0
    if [[ "$TARGET" != *:* ]]; then
        TARGET="${TARGET}:0.0"
    # If target is session:window (has colon but no dot), append .0
    elif [[ "$TARGET" != *.* ]]; then
        TARGET="${TARGET}.0"
    fi
fi
shift

MSG="$*"
if [ "$PREFIX_MODE" -eq 1 ] && [ -n "$TMUX" ]; then
    SENDER=$(tmux display-message -p '#S:#{window_index}.#{pane_index}')
    MSG="${SENDER}: ${MSG}"
fi

BUF="nudge-$$-$RANDOM"
tmux set-buffer -b "$BUF" -- "$MSG"
tmux paste-buffer -b "$BUF" -p -t "$TARGET"
sleep "${TMUX_SEND_ENTER_DELAY:-0.1}"
tmux send-keys -t "$TARGET" C-m
tmux delete-buffer -b "$BUF" 2>/dev/null