setup.sh: fix some bugs

setup.sh

@@ -9,6 +9,7 @@ __setups="shrc_common gitconf tmux scripts darwin dirs selfupdate windirs dotfil
 __homelocal="$HOME/.local"
 __homevar="$HOME/.var"
 __dotfiles_dir_default="$HOME/10sr_dotfiles"
+_current_date=`date`
 
 # TODO: how to give args to command?
 
@@ -167,7 +168,7 @@ setup_shrc_common(){
 #!/bin/sh
 
 # $__shrc_common
-# Automatically generated by $0
+# Automatically generated by $0 at $_current_date
 
 ismsys=$ismsys
 iscygwin=$iscygwin
@@ -277,9 +278,9 @@ setup_tmux(){
             ;;
     esac
 
-    _date=`date` cat <<__EOC__ >"$tmux_conf_local"
+    cat <<__EOC__ >"$tmux_conf_local"
 # $tmux_conf_local
-# Automatically generated by $0 at $_date
+# Automatically generated by $0 at $_current_date
 
 set -g status-right "${USER}@$(hostname) | #(tmux -V) "
 
@@ -299,6 +300,7 @@ _fetch_script(){
     url="$1"
     name="$2"
     dst="$HOME/.local/bin/$name"
+    test -f "$dst" && return 0
     command -v "$name" >/dev/null && return 0
     if _download "$url" "$dst"
     then