tmux split + auto start

.tmux.conf

# @author madebycm (2025-06-02)
# tmux configuration - streamlined setup for macOS Terminal

# ====================
# PREFIX KEY
# ====================
# Change prefix from default Ctrl+B to Ctrl+Space for easier access
set -g prefix C-Space
unbind C-b
bind C-Space send-prefix

# ====================
# PANE MANAGEMENT
# ====================
# Unbind default split keys
unbind '"'
unbind %

# Intuitive split bindings:
bind - split-window -h    # Ctrl+Space + - = vertical split (side by side)
bind h split-window -v    # Ctrl+Space + h = horizontal split (top/bottom)

# Switch between panes:
bind j select-pane -L    # Ctrl+Space + j = left pane
bind k select-pane -R    # Ctrl+Space + k = right pane  
bind i select-pane -U    # Ctrl+Space + i = up pane
bind o select-pane -D    # Ctrl+Space + o = down pane

# Resize panes (repeatable - hold prefix once, then press arrows multiple times):
bind -r Left resize-pane -L 5     # Ctrl+Space + Left = shrink left
bind -r Right resize-pane -R 5    # Ctrl+Space + Right = grow right
bind -r Up resize-pane -U 5       # Ctrl+Space + Up = shrink up
bind -r Down resize-pane -D 5     # Ctrl+Space + Down = grow down

# ====================
# MOUSE & DISPLAY
# ====================
# Enable mouse support (click to switch panes, drag to resize)
set -g mouse on

# Better colors
set -g default-terminal "screen-256color"

# Start windows and panes at 1 instead of 0 (easier to reach on keyboard)
set -g base-index 1
setw -g pane-base-index 1

# ====================
# UTILITIES  
# ====================
# Reload config file
bind r source-file ~/.tmux.conf \; display-message "Config reloaded!"

# ====================
# AUTO-START SETUP
# ====================
# To auto-start tmux when opening Terminal, add this to ~/.zshrc:
#
# # Auto-start tmux
# if [ -z "$TMUX" ] && [ ${UID} != 0 ] && [[ $- == *i* ]]; then
#     tmux source-file ~/.tmux.conf 2>/dev/null || true
#     tmux new-session -A -s main
# fi
#
# This will:
# - Auto-reload this config file on terminal start
# - Create/attach to a session called "main"
# - Only run for interactive shells (not scripts or root)

# ====================
# QUICK REFERENCE
# ====================
# Ctrl+Space + - : vertical split
# Ctrl+Space + h : horizontal split  
# Ctrl+Space + j/k/i/o : switch panes (left/right/up/down)
# Ctrl+Space + arrows : resize panes
# Ctrl+Space + r : reload config
# Mouse: click panes to switch, drag borders to resize