SSH Terminal Issues

# Symptom: "WARNING: terminal is not fully functional"
# or keys/colors broken after SSH

# Cause: remote system lacks terminfo entry for your $TERM
echo $TERM                               # e.g., "tmux-256color"
# Remote may not have tmux-256color in its terminfo database

# Fix 1: Copy terminfo to remote
infocmp -x | ssh remote 'tic -x /dev/stdin'

# Fix 2: Override TERM
ssh -t remote 'TERM=xterm-256color exec bash'

# Fix 3: Set in SSH config
# Host remote
#   SetEnv TERM=xterm-256color

# Symptom: garbled characters, broken box-drawing

# Check local
locale                                   # should show UTF-8

# Check remote
ssh remote 'locale'

# Fix: set locale on remote
# In remote's ~/.bashrc or ~/.zshrc:
# export LANG=en_US.UTF-8
# export LC_ALL=en_US.UTF-8

# Fix: forward locale (SSH config)
# SendEnv LANG LC_*                      # in ssh_config
# AcceptEnv LANG LC_*                    # in remote sshd_config

# Symptom: "Write failed: Broken pipe" or frozen terminal

# Client-side keepalive (~/.ssh/config)
# Host *
#   ServerAliveInterval 60               # send keepalive every 60s
#   ServerAliveCountMax 3                # disconnect after 3 missed

# Server-side (/etc/ssh/sshd_config)
# ClientAliveInterval 60
# ClientAliveCountMax 3

# Escape sequence: unstick frozen SSH
# ~.                                     # disconnect (must be at line start)
# ~?                                     # show escape help
# ~~                                     # literal tilde

# Modern terminals support OSC 52 for remote clipboard

# Copy text to local clipboard from remote
printf "\e]52;c;%s\a" "$(echo -n 'text to copy' | base64)"

# Terminal must support it:
# Alacritty: osc52 = "CopyPaste" in config
# Kitty: clipboard_control write-clipboard
# tmux: set -g set-clipboard on

# Neovim over SSH (uses OSC 52 automatically with recent versions)
# :set clipboard=unnamedplus

# Symptom: no colors or wrong colors in remote vim/tmux

# Check color support
tput colors                              # should be 256

# Force 256 colors
export TERM=xterm-256color

# tmux inside SSH: chain correctly
# Local tmux.conf:
# set -g default-terminal "tmux-256color"
# Remote bashrc:
# if [ -n "$TMUX" ]; then export TERM=tmux-256color; fi

# True color test
printf "\e[38;2;255;0;0mRED\e[0m "
printf "\e[38;2;0;255;0mGREEN\e[0m "
printf "\e[38;2;0;0;255mBLUE\e[0m\n"

# Symptom: lines wrap wrong, vim draws incorrectly after resize

# Check terminal size
stty size                                # rows cols
tput lines; tput cols

# Force resize notification
kill -WINCH $$                           # send SIGWINCH to current shell

# After serial console or old SSH
stty rows 50 cols 200                    # manually set size
resize                                   # auto-detect (xterm)

# Reset broken terminal
reset                                    # full terminal reset
stty sane                                # reset stty settings
tput reset                               # terminfo reset