SSH title support

zsh.d/prompts/pure/pure.zsh

@@ -621,6 +621,51 @@ prompt_pure_reset_vim_prompt_widget() {
 }
 
 prompt_pure_state_setup() {
+	setopt localoptions noshwordsplit
+
+	# Check SSH_CONNECTION and the current state.
+	local ssh_connection=${SSH_CONNECTION:-$PROMPT_PURE_SSH_CONNECTION}
+	local username hostname
+
+	if [[ -z $ssh_connection ]] && (( $+commands[who] )); then
+		# When changing user on a remote system, the $SSH_CONNECTION
+		# environment variable can be lost. Attempt detection via `who`.
+		local who_out
+		who_out=$(who -m 2>/dev/null)
+		if (( $? )); then
+			# Who am I not supported, fallback to plain who.
+			local -a who_in
+			who_in=( ${(f)"$(who 2>/dev/null)"} )
+			who_out="${(M)who_in:#*[[:space:]]${TTY#/dev/}[[:space:]]*}"
+		fi
+
+		local reIPv6='(([0-9a-fA-F]+:)|:){2,}[0-9a-fA-F]+'  # Simplified, only checks partial pattern.
+		local reIPv4='([0-9]{1,3}\.){3}[0-9]+'   # Simplified, allows invalid ranges.
+		# Here we assume two non-consecutive periods represents a
+		# hostname. This matches `foo.bar.baz`, but not `foo.bar`.
+		local reHostname='([.][^. ]+){2}'
+
+		# Usually the remote address is surrounded by parenthesis, but
+		# not on all systems (e.g. busybox).
+		local -H MATCH MBEGIN MEND
+		if [[ $who_out =~ "\(?($reIPv4|$reIPv6|$reHostname)\)?\$" ]]; then
+			ssh_connection=$MATCH
+
+			# Export variable to allow detection propagation inside
+			# shells spawned by this one (e.g. tmux does not always
+			# inherit the same tty, which breaks detection).
+			export PROMPT_PURE_SSH_CONNECTION=$ssh_connection
+		fi
+		unset MATCH MBEGIN MEND
+	fi
+
+	hostname='%F{$prompt_pure_colors[host]}@%m%f'
+	# Show `username@host` if logged in through SSH.
+	[[ -n $ssh_connection ]] && username='%F{$prompt_pure_colors[user]}%n%f'"$hostname"
+
+	# # Show `username@host` if root, with username in default color.
+	# [[ $UID -eq 0 ]] && username='%F{$prompt_pure_colors[user:root]}%n%f'"$hostname"
+
   typeset -gA prompt_pure_state
   prompt_pure_state[version]="1.11.0"
   prompt_pure_state+=(