Support only Tmux v1.9 or greater

Closes #1

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### master
 - saving a new session does not remove the previous one
 - make the directory where sessions are stored configurable
+- support only Tmux v1.9 or greater
 
 ### v0.0.1, 2014-08-26
 - started a project

scripts/check_tmux_version.sh

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+
+VERSION="$1"
+UNSUPPORTED_MSG="$2"
+
+get_tmux_option() {
+	local option=$1
+	local default_value=$2
+	local option_value=$(tmux show-option -gqv "$option")
+	if [ -z "$option_value" ]; then
+		echo "$default_value"
+	else
+		echo "$option_value"
+	fi
+}
+
+# Ensures a message is displayed for 5 seconds in tmux prompt.
+# Does not override the 'display-time' tmux option.
+display_message() {
+	local message="$1"
+
+	# display_duration defaults to 5 seconds, if not passed as an argument
+	if [ "$#" -eq 2 ]; then
+		local display_duration="$2"
+	else
+		local display_duration="5000"
+	fi
+
+	# saves user-set 'display-time' option
+	local saved_display_time=$(get_tmux_option "display-time" "750")
+
+	# sets message display time to 5 seconds
+	tmux set-option -gq display-time "$display_duration"
+
+	# displays message
+	tmux display-message "$message"
+
+	# restores original 'display-time' value
+	tmux set-option -gq display-time "$saved_display_time"
+}
+
+# this is used to get "clean" integer version number. Examples:
+# `tmux 1.9` => `19`
+# `1.9a`     => `19`
+get_digits_from_string() {
+	local string="$1"
+	local only_digits="$(echo "$string" | tr -dC '[:digit:]')"
+	echo "$only_digits"
+}
+
+tmux_version_int() {
+	local tmux_version_string=$(tmux -V)
+	echo "$(get_digits_from_string "$tmux_version_string")"
+}
+
+unsupported_version_message() {
+	if [ -n "$UNSUPPORTED_MSG" ]; then
+		echo "$UNSUPPORTED_MSG"
+	else
+		echo "Error, Tmux version unsupported! Please install Tmux version $VERSION or greater!"
+	fi
+}
+
+exit_if_unsupported_version() {
+	local current_version="$1"
+	local supported_version="$2"
+	if [ "$current_version" -lt "$supported_version" ]; then
+		display_message "$(unsupported_version_message)"
+		exit 1
+	fi
+}
+
+main() {
+	local supported_version_int="$(get_digits_from_string "$VERSION")"
+	local current_version_int="$(tmux_version_int)"
+	exit_if_unsupported_version "$current_version_int" "$supported_version_int"
+}
+main

scripts/helpers.sh

@@ -2,6 +2,8 @@
 default_sessions_dir="$HOME/.tmux/sessions"
 sessions_dir_option="@sessions-dir"
 
+SUPPORTED_VERSION="1.9"
+
 # helper functions
 get_tmux_option() {
 	local option="$1"
@@ -39,6 +41,13 @@ display_message() {
 	tmux set-option -gq display-time "$saved_display_time"
 }
 
+
+supported_tmux_version_ok() {
+	$CURRENT_DIR/check_tmux_version.sh "$SUPPORTED_VERSION"
+}
+
+# path helpers
+
 sessions_dir() {
 	echo $(get_tmux_option "$sessions_dir_option" "$default_sessions_dir")
 }

scripts/session_restorer.sh

@@ -75,6 +75,8 @@ restore_all_sessions() {
 }
 
 main() {
+	if supported_tmux_version_ok; then
 		restore_all_sessions
+	fi
 }
 main

scripts/session_saver.sh

@@ -30,6 +30,8 @@ save_all_sessions() {
 }
 
 main() {
+	if supported_tmux_version_ok; then
 		save_all_sessions
+	fi
 }
 main