diff --git a/README.md b/README.md
index c108fed..9ea7573 100644
--- a/README.md
+++ b/README.md
@@ -3,23 +3,35 @@ t
 
 NAME
 ----
-t -- easy tmux wrapper
+t - Easy tmux wrapper
 
 USAGE
 ----
-    * t session_name [TMUX_OPTIONS]  # Find or create tmux-session, and attach this.
-    * t [-S|-s|--sock] socket_path   # Find or create socket, And attach this session.
-    * t [-l|--list] [session|window] # Show alive tmux sessions.
-    * t [-k|--kill] session_name     # Kill session. (default is current)
-    * t [-f|--prefix] [key]          # Rebind tmux prefix-key.
-    * t [-d|--detach]                # Detach current session.
-    * t [-m|--mouse]                 # Mouse mode on/off toggle.
-
+```
+ * t session_name [TMUX_OPTIONS]                # Find or create tmux-session, and detach any other client then attach this.
+ *     [-A|-a|--attach] session_name            # Find or create tmux-session, and attach this.
+ *     [--ad|--attach-with-detach] session_name # Find or create tmux-session, and attach this.
+ *     [-S|-s|--sock] socket_path               # Find or create socket, And attach this session.
+ *     [-l|--list] [session|window]             # Show alive tmux sessions.
+ *     [-k|--kill] session_name                 # Kill session. (default is current)
+ *     [-f|--prefix] [key]                      # Rebind tmux prefix-key.
+ *     [-d|--detach]                            # Detach current session.
+ *     [-m|--mouse]                             # Mouse mode on/off toggle.
+```
+
+ENVIRONMENTS
+---
+```
+ T_DEFAULT_SESSIONNAME             # Default use session_name (default: "main")
+ T_DEFAULT_SOCKPATH                # Default use socket_path (default: "~/tmp//tmux-socket")
+ T_DEFAULT_TMUX_OPTION             # Default tmux cmd optoin (default: "")
+ T_DEFAULT_TMUX_ATTACH_WITH_DETACH # Each other tty detach then attach session, when using `t` without specification. (default "on")
+```
 
 
 Author
 
-Copyright (c) 2015 - 2018 Hiroshi IKEGAMI
+Copyright (c) 2015 - 2021 Hiroshi IKEGAMI
 
 MIT License
 
diff --git a/t b/t
index 8cc7a95..9296491 100755
--- a/t
+++ b/t
@@ -1,27 +1,23 @@
 #! /bin/bash
 
 #
-# t
-# ====
-#
-# NAME
-# ----
-# t -- easy tmux wrapper
+# t - Easy tmux wrapper
 #
 # USAGE
 # ----
-#     * t session_name [TMUX_OPTIONS]  # Find or create tmux-session, and detach any other client then attach this.
-#     * t [-a|--attach] session_name   # Find or create tmux-session, and attach this.
-#     * t [-S|-s|--sock] socket_path   # Find or create socket, And attach this session.
-#     * t [-l|--list] [session|window] # Show alive tmux sessions.
-#     * t [-k|--kill] session_name     # Kill session. (default is current)
-#     * t [-f|--prefix] [key]          # Rebind tmux prefix-key.
-#     * t [-d|--detach]                # Detach current session.
-#     * t [-m|--mouse]                 # Mouse mode on/off toggle.
+#     * t session_name [TMUX_OPTIONS]                # Find or create tmux-session, and detach any other client then attach this.
+#     *     [-A|-a|--attach] session_name            # Find or create tmux-session, and attach this.
+#     *     [--ad|--attach-with-detach] session_name # Find or create tmux-session, and attach this.
+#     *     [-S|-s|--sock] socket_path               # Find or create socket, And attach this session.
+#     *     [-l|--list] [session|window]             # Show alive tmux sessions.
+#     *     [-k|--kill] session_name                 # Kill session. (default is current)
+#     *     [-f|--prefix] [key]                      # Rebind tmux prefix-key.
+#     *     [-d|--detach]                            # Detach current session.
+#     *     [-m|--mouse]                             # Mouse mode on/off toggle.
 #
 # Author
 #
-# Copyright (c) 2015 - 2020 Hiroshi IKEGAMI
+# Copyright (c) 2015 - 2021 Hiroshi IKEGAMI
 #
 # MIT License
 #
@@ -49,27 +45,29 @@
 
 set -e
 export LANG=C
-export TMUX_DEFAULT_SESSIONNAME="main"
-export TMUX_DEFAULT_SOCKPATH="~/tmp//tmux-socket"
-export TMUX_DEFAULT_SUPPORT_COLOURS=256
+export T_DEFAULT_SESSIONNAME="${T_DEFAULT_SESSIONNAME:-"main"}"
+export T_DEFAULT_SOCKPATH="${T_DEFAULT_SOCKPATH:-"~/tmp//tmux-socket"}"
+export T_DEFAULT_TMUX_OPTION="${T_DEFAULT_TMUX_OPTION:-""}"
+export T_DEFAULT_TMUX_ATTACH_WITH_DETACH="${T_DEFAULT_TMUX_OPTION:-"on"}"
 
 
-__usage_exit() {
-    cat << HELP
+t::usage_exit() {
+    cat << HELP >&2
 USAGE:
-    * t session_name                 # Find or create tmux-session, and detach any other client then attach this.
-    * t [-a|--attach] session_name   # Find or create tmux-session, and attach this.
-    * t [-S|-s|--sock] socket_path   # Find or create socket, And attach this session.
-    * t [-l|--list] [session|window] # Show alive tmux sessions.
-    * t [-k|--kill] session_name     # Kill session. (default is current)
-    * t [-f|--prefix] [key]          # Rebind tmux prefix-key.
-    * t [-d|--detach]                # Detach current session.
-    * t [-m|--mouse]                 # Mouse mode on/off toggle.
+    * t session_name [TMUX_OPTIONS]                # Find or create tmux-session, and detach any other client then attach this.
+    *     [-A|-a|--attach] session_name            # Find or create tmux-session, and attach this.
+    *     [--ad|--attach-with-detach] session_name # Find or create tmux-session, and attach this.
+    *     [-S|-s|--sock] socket_path               # Find or create socket, And attach this session.
+    *     [-l|--list] [session|window]             # Show alive tmux sessions.
+    *     [-k|--kill] session_name                 # Kill session. (default is current)
+    *     [-f|--prefix] [key]                      # Rebind tmux prefix-key.
+    *     [-d|--detach]                            # Detach current session.
+    *     [-m|--mouse]                             # Mouse mode on/off toggle.
 HELP
     exit 1
 }
 
-__tmux_rebind_prefix() {
+t::tmux_rebind_prefix() {
     local _new_key_="C-${1}"
     local _old_key_="C-$(tmux list-key | grep send-prefix | perl -p -e "s/.*C-([\\w]).*/\$1/")"
 
@@ -86,82 +84,76 @@ HELP
     fi
 }
 
-__tmux_attach_simple() {
+t::tmux_attach() {
     if [ ! -z ${TMUX} ];then
         echo 'sessions should be nested with care, unset $TMUX to force';
         return 1;
     fi
-    local session_name="${1:-"${TMUX_DEFAULT_SESSIONNAME}"}";
+    local session_name="${1:-"${T_DEFAULT_SESSIONNAME}"}";
     if [ "$#" != 0 ];then
         shift
     fi
     session_exists=$(tmux ls 2>&1 | cut -d ':' -f 1 | grep -e "^${session_name}$" | wc -l | perl -pe "s/\s//g")
     if [ "${session_exists}" = 0 ]; then
-        tmux new-session -s "${session_name}"
+        tmux new-session -s "${session_name}" $@ ${T_DEFAULT_TMUX_OPTION}
     else
-        tmux attach -t "${session_name}"
+        if [ ${T_TMUX_ATTACH_WITH_DETACH} = "on" ];then
+            tmux attach -d -t "${session_name}" $@ ${T_DEFAULT_TMUX_OPTION}
+        else
+            tmux attach -t "${session_name}" $@ ${T_DEFAULT_TMUX_OPTION}
+        fi
     fi
 }
 
-__tmux_attach() {
-    if [ ! -z ${TMUX} ];then
+t::tmux_sock() {
+    if [[ ! -z ${TMUX} ]];then
         echo 'sessions should be nested with care, unset $TMUX to force';
         return 1;
     fi
-    local session_name="${1:-"${TMUX_DEFAULT_SESSIONNAME}"}";
-    if [ "$#" != 0 ];then
-        shift
-    fi
-    session_exists=$(tmux ls 2>&1 | cut -d ':' -f 1 | grep -e "^${session_name}$" | wc -l | perl -pe "s/\s//g")
-    if [ "${session_exists}" = 0 ]; then
-        tmux new-session -s "${session_name}" $@
-    else
-        tmux attach -d -t "${session_name}" $@
-    fi
-}
-
-__tmux_sock() {
-    if [ ! -z ${TMUX} ];then
-        echo 'sessions should be nested with care, unset $TMUX to force';
-        return 1;
-    fi
-    local socket_path="${TMUX_DEFAULT_SOCKPATH}";
+    local socket_path="${T_DEFAULT_SOCKPATH}";
     [ $# -ne '0' ] && socket_path="$1";
     if [ -e "${socket_path}" ]; then
         mkdir -p "$(dirname "${socket_path}")"
-        tmux -S "${socket_path}"
+        tmux -S "${socket_path}" ${T_DEFAULT_TMUX_OPTION}
     else
-        tmux -S "${socket_path}" attach
+        tmux -S "${socket_path}" attach ${T_DEFAULT_TMUX_OPTION}
     fi
 }
 
-__tmux_mouse() {
+t::tmux_mouse() {
 
-    [ "${TMUX_MOUSEMODE}" = '' ] && export TMUX_MOUSEMODE="$(tmux show -g | grep mouse-resize-pane | perl -p -e 's/mouse-resize-pane //')";
+    [ "${T_TMUX_MOUSEMODE}" = '' ] && \
+        export T_TMUX_MOUSEMODE="$(tmux show -g | \
+        grep mouse-resize-pane | \
+        perl -p -e 's/mouse-resize-pane //')";
 
     if [ "${TMUX_MOUSEMODE}" == 'on' ];then
-        local switch=off
+        local switch="off"
     else
-        local switch=on
+        local switch="on"
     fi
 
     tmux set-option -g mouse-select-pane ${switch}
     tmux set-option -g mode-mouse ${switch}
     tmux set-option -g mouse-resize-pane ${switch}
     tmux set-option -g mouse-select-pane ${switch}
-    export TMUX_MOUSEMODE=${switch}
+    export T_TMUX_MOUSEMODE=${switch}
 
 }
 
 
-optspec=":a:f:s:k:-:hldm"
+optspec=":A:a:f:S:s:k:-:hldm"
 while getopts "$optspec" optchar; do
     case "${optchar}" in
         -)
             case "${OPTARG}" in
                 attach)
                     val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
-                    __tmux_attach_simple "${val}"; exit 0
+                    env T_TMUX_ATTACH_WITH_DETACH=0 t::tmux_attach "${val}"; exit 0
+                    ;;
+                ad|attach-with-detach)
+                    val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
+                    env T_TMUX_ATTACH_WITH_DETACH=1 t::tmux_attach "${val}"; exit 0
                     ;;
                 detach)
                     \tmux detach-client; exit 1
@@ -171,21 +163,21 @@ while getopts "$optspec" optchar; do
                     \tmux kill-session -t "${val}"; exit 1
                     ;;
                 mouse)
-                    __tmux_mouse; exit 0
+                    t::tmux_mouse; exit 0
                     ;;
                 prefix)
                     val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
-                    __tmux_rebind_prefix "${val}"; exit 0
+                    t::tmux_rebind_prefix "${val}"; exit 0
                     ;;
                 sock)
                     val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
-                    __tmux_sock "${val}"; exit 0
+                    t::tmux_sock "${val}"; exit 0
                     ;;
                 list)
                     \tmux ls; exit 0
                     ;;
                 help)
-                    __usage_exit; exit 1
+                    t::usage_exit; exit 1
                     ;;
                 *)
                     if [ "$OPTERR" = 1 ] && [ "${optspec:0:1}" != ":" ]; then
@@ -194,13 +186,13 @@ while getopts "$optspec" optchar; do
                     ;;
             esac;;
         h)
-            __usage_exit; exit 1
+            t::usage_exit; exit 1
             ;;
         l)
             \tmux ls; exit 0
             ;;
-        a)
-            __tmux_attach_simple "${OPTARG}"; exit 0
+        A|a)
+            t::tmux_attach "${OPTARG}"; exit 0
             ;;
         d)
             \tmux detach-client; exit 1
@@ -208,11 +200,11 @@ while getopts "$optspec" optchar; do
         k)
             \tmux kill-session -t "${OPTARG}"; exit 1
             ;;
-        s)
-            __tmux_sock "${OPTARG}"; exit 0
+        S|s)
+            t::tmux_sock "${OPTARG}"; exit 0
             ;;
         m)
-            __tmux_mouse; exit 0
+            t::tmux_mouse; exit 0
             ;;
         *)
             if [ "$OPTERR" != 1 ] || [ "${optspec:0:1}" = ":" ]; then
@@ -223,4 +215,6 @@ while getopts "$optspec" optchar; do
     esac
 done
 
-__tmux_attach $@
+export T_TMUX_ATTACH_WITH_DETACH="${T_DEFAULT_TMUX_ATTACH_WITH_DETACH}" && \
+    t::tmux_attach $@ && exit 0;
+
diff --git a/t.1 b/t.1
index 0c31587..00a575e 100644
--- a/t.1
+++ b/t.1
@@ -1,43 +1,83 @@
+.nh
 .TH t
 .SH NAME
 .PP
-t \-\- easy tmux wrapper
+t \- easy tmux wrapper
+
 .SH USAGE
 .PP
 .RS
+
 .nf
-* t session_name [TMUX_OPTIONS]  # Find or create tmux-session, and detach any other client then attach this.
-* t [-a|--attach] session_name   # Find or create tmux-session, and attach this.
-* t [\-S|\-s|\-\-sock] socket_path   # Find or create socket, And attach this session.
-* t [\-l|\-\-list] [session|window] # Show alive tmux sessions.
-* t [\-k|\-\-kill] session_name     # Kill session. (default is current)
-* t [\-f|\-\-prefix] [key]          # Rebind tmux prefix\-key.
-* t [\-d|\-\-detach]                # Detach current session.
-* t [\-m|\-\-mouse]                 # Mouse mode on/off toggle.
+ * t session\_name [TMUX\_OPTIONS]                # Find or create tmux\-session, and detach any other client then attach this.
+ *     [\-A|\-a|\-\-attach] session\_name            # Find or create tmux\-session, and attach this.
+ *     [\-\-ad|\-\-attach\-with\-detach] session\_name # Find or create tmux\-session, and attach this.
+ *     [\-S|\-s|\-\-sock] socket\_path               # Find or create socket, And attach this session.
+ *     [\-l|\-\-list] [session|window]             # Show alive tmux sessions.
+ *     [\-k|\-\-kill] session\_name                 # Kill session. (default is current)
+ *     [\-f|\-\-prefix] [key]                      # Rebind tmux prefix\-key.
+ *     [\-d|\-\-detach]                            # Detach current session.
+ *     [\-m|\-\-mouse]                             # Mouse mode on/off toggle.
+
 .fi
 .RE
+
+.SH ENVIRONMENTS
+.PP
+.RS
+
+.nf
+ T\_DEFAULT\_SESSIONNAME             # Default use session\_name (default: "main")
+ T\_DEFAULT\_SOCKPATH                # Default use socket\_path (default: "~/tmp//tmux\-socket")
+ T\_DEFAULT\_TMUX\_OPTION             # Default tmux cmd optoin (default: "")
+ T\_DEFAULT\_TMUX\_ATTACH\_WITH\_DETACH # Each other tty detach then attach session, when using `t` without specification. (default "on")
+
+.fi
+.RE
+
 .PP
 Author
+
 .PP
-Copyright (c) 2015 \- 2020 Hiroshi IKEGAMI
+Copyright (c) 2015 \- 2021 Hiroshi IKEGAMI
+
 .PP
 MIT License
+
 .PP
 Permission is hereby granted, free of charge, to any person obtaining
+.br
 a copy of this software and associated documentation files (the
+.br
 "Software"), to deal in the Software without restriction, including
+.br
 without limitation the rights to use, copy, modify, merge, publish,
+.br
 distribute, sublicense, and/or sell copies of the Software, and to
+.br
 permit persons to whom the Software is furnished to do so, subject to
+.br
 the following conditions:
+.br
+
 .PP
 The above copyright notice and this permission notice shall be
+.br
 included in all copies or substantial portions of the Software.
+.br
+
 .PP
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+.br
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+.br
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+.br
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+.br
 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+.br
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+.br
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+.br