diff --git a/README.md b/README.md
index 22a6c08..62c45ad 100644
--- a/README.md
+++ b/README.md
@@ -6,13 +6,15 @@ Invocation
 ----------
 
 To run cdm, use
-	$ cdm [RCFILE]
+
+    $ cdm [RCFILE]
 
 cdm tries to source configuration files in this order, and uses the first
 existing one:
-	[RCFILE specified on command line]
-	$HOME/.cdmrc
-	/etc/cdmrc
+
+    [RCFILE specified on command line]
+    $HOME/.cdmrc
+    /etc/cdmrc
 
 To autostart cdm when you log in your account, copy the content of
 /usr/share/doc/cdm/profile.sh to the tail of your shell profile (~/.profile,
@@ -37,7 +39,7 @@ Thanks to:
     tigrmesh        finding a critical issue with the gnome-session handler
     Profjim         several incredibly useful patches
     lambchops468    consolekit and hibernation patches
-    CasperVector    Massive rearchitecturing and code sanisation
+    CasperVector    Massive rearchitecturing and code sanitation
 
 Licensed under GPLv2+
 
diff --git a/src/cdm b/src/cdm
index 3663685..6c0b529 100755
--- a/src/cdm
+++ b/src/cdm
@@ -48,7 +48,7 @@ yesno()
     case "$value" in
         [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) return 0;; 
         [Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0) return 1;; 
-        *) warn "Invalid value for \`$1'; falling back to \`no' for now.";;
+        *) warn "invalid value for \`$1'; falling back to \`no' for now.";;
     esac
 }
 
@@ -70,27 +70,25 @@ fi
 
 # Default options.
 
-binlist=${binlist:-()}
-namelist=${namelist:-()}
-flaglist=${flaglist:-()}
 dialogrc=${dialogrc:-}
 countfrom=${countfrom:-0}
 display=${display:-0}
 xtty=${xtty:-7}
 locktty=${locktty:-no}
-serverargs=${serverargs:-'-nolisten tcp'}
 consolekit=${consolekit:-yes}
 cktimeout=${cktimeout:-30}
+[[ -z "${binlist[*]}" ]] && binlist=()
+[[ -z "${namelist[*]}" ]] && namelist=()
+[[ -z "${flaglist[*]}" ]] && flaglist=()
+[[ -z "${serverargs[*]}" ]] && serverargs=(-nolisten tcp)
 
 # Offer all available sessions in /etc/X11/Sessions,
-# if binlist if not explicitly set in cdmrc.
+# if $binlist if not explicitly set in cdmrc.
 
-if [[ "$binlist" == "()" ]]; then
+if [[ "${#binlist[@]}" == 0 ]]; then
     binlist=($(find /etc/X11/Sessions -maxdepth 1 -type f))
-    for ((i=0; i<${#binlist[@]}; i++)); do
-        declare flaglist[$i]="X"
-        declare namelist[$i]=$(basename ${binlist[$i]})
-    done
+    flaglist=($(sed 's/[[:digit:]]\+/X/g' <<< ${!binlist[@]}))
+    namelist=(${binlist[@]##*/})
 fi
 
 # Generate the main menu.
@@ -106,7 +104,7 @@ else
     # Display selection dialog.
     binindex=$(
         DIALOGRC="$dialogrc" dialog --colors --stdout \
-        --backtitle "${longname} v${ver}" \
+        --backtitle "$longname v$ver" \
         --ok-label ' Select ' --cancel-label ' Exit ' \
         --menu 'Select session' 0 0 0 "${menu[@]}"
     )
@@ -118,34 +116,33 @@ fi
 
 # Run $bin according to its flag.
 let binindex-=countfrom
-bin="${binlist[${binindex}]}"
+bin=($(eval echo "${binlist[${binindex}]}"))
 case ${flaglist[$binindex]} in
     # *C*onsole programs.
     [Cc])
         clear
+
         # If $bin is a login shell, it might `exec' cdm again, causing an endless
         # loop. To solve this problem, export $CDM_SPAWN when `exec'ing $bin and
         # only let the shell automatically `exec' cdm when $CDM_SPAWN is not set.
         # See also the example shell profile file shipped with the cdm package.
 
         # Also untrap SIGINT and SIGTSTP before spawning process: If this is not
-        # done, *ANY* child process of *ANY* child (bash) shell will completely
+        # done, any child process of any child (bash) shell will completely
         # ignore SIGINT, which is rather confusing, and cannot be undone.
 
         trap - SIGINT SIGTSTP
-        CDM_SPAWN=$$ exec $bin
+        CDM_SPAWN=$$ exec "${bin[@]}"
         ;;
 
     # *X* programs.
     [Xx])
         clear
 
-        # If X is already running and locktty=yes, activate it
-        if $(yesno locktty); then
-            if xdpyinfo -display ":$display.0" &> /dev/null; then
-                chvt "$((display+xtty))"
-                exitnormal
-            fi
+        # If X is already running and locktty=yes, activate it.
+        if $(yesno locktty) && xdpyinfo -display ":$display.0" &> /dev/null; then
+            chvt "$((display+xtty))"
+            exitnormal
         fi
 
         # Get the first empty display.
@@ -163,27 +160,27 @@ case ${flaglist[$binindex]} in
             fi
         done
 
-        # run X in current tty
-        if [[ $xtty == "keep" ]]; then
-            vt=$(tty)
-            vt=${vt#/dev/}
-            if [[ $vt != tty* ]]; then
-                error "error: invalid TTY"
+        # Support for running X in current tty.
+        if [[ $xtty == 'keep' ]]; then
+            vt="$(tty)"
+            if [[ "$vt" != '/dev/tty'* ]]; then
+                error 'invalid TTY.'
                 exiterror
             fi
-            vt=${vt#tty}
+            vt="${vt#/dev/tty}"
         else
-            vt=$((xtty+display))
+            vt="$((xtty+display))"
         fi
 
-        serverargs=":${display} $serverargs vt$vt"
+        serverargs=(":${display}" "${serverargs[@]}" "vt$vt")
 
-        $(yesno consolekit) && launchflags="-c -t $cktimeout"
-        if ! eval cdm-xlaunch $launchflags -- $bin -- $serverargs; then
+        $(yesno consolekit) && launchflags=(-c -t "$cktimeout")
+        if cdm-xlaunch "${launchflags[@]}" -- "${bin[@]}" -- "${serverargs[@]}"
+        then
+            exitnormal
+        else
             warn "\`cdm-xlaunch' exited unsuccessfully."
             exiterror
-        else
-            exitnormal
         fi
         ;;
 
@@ -193,4 +190,4 @@ case ${flaglist[$binindex]} in
         ;;
 esac
 
-# vim:set ts=4 sw=4 et:
+# vim:ts=4:sw=4:et
diff --git a/src/cdm-xlaunch b/src/cdm-xlaunch
index e6b4986..5535ec7 100755
--- a/src/cdm-xlaunch
+++ b/src/cdm-xlaunch
@@ -56,7 +56,7 @@ done
 
 # Do first to avoid race conditions.
 if $consolekit; then
-    info "waiting for ConsoleKit to register X session."
+    info 'waiting for ConsoleKit to register X session.'
     sleep "$cktimeout" & clockpid=$!
     dbuspidfifo=$(mktemp --dry-run --tmpdir $name.XXXXXXXX)
     if ! mkfifo "$dbuspidfifo"; then
@@ -77,7 +77,7 @@ if $consolekit; then
 fi
 
 # Conform to POSIX and do not use `>&' here.
-setsid startx $* > /dev/null 2>&1 &
+setsid startx "$@" > /dev/null 2>&1 &
 
 # If wait(1) returns with a value >128, it was interrupted by kill(1),
 # so registration was sucessful.
@@ -86,14 +86,14 @@ if $consolekit; then
         if wait "$clockpid" >& /dev/null
         then
             kill "$dbuspid"
-            error "ConsoleKit registration timed out."
+            error 'ConsoleKit registration timed out.'
             exit 1
         else
             kill "$dbuspid"
-            info "ConsoleKit registration succeeded."
+            info 'ConsoleKit registration succeeded.'
             exit 0
         fi
     fi
 fi
 
-# vim:set ts=4 sw=4 et:
+# vim:ts=4:sw=4:et
diff --git a/src/cdmrc b/src/cdmrc
index 1d0525c..07ef72f 100644
--- a/src/cdmrc
+++ b/src/cdmrc
@@ -8,17 +8,17 @@
 #
 # (An example:)
 # binlist=(
-#   "~/.xsession"                    # Launch your X session,
-#   "/bin/bash --login"              # or just execute your shell,
-#   "/usr/bin/fbterm"                # or start a frame buffer console,
-#   "/usr/bin/cdm ~/.submenu.cdmrc"  # or go to a submenu :)
+#   '~/.xsession'                    # Launch your X session,
+#   '/bin/bash --login'              # or just execute your shell,
+#   '/usr/bin/fbterm'                # or start a frame buffer console,
+#   '/usr/bin/cdm ~/.submenu.cdmrc'  # or go to a submenu :)
 # )
 
 # List all program display names, one-by-one matched with $binlist.
 # Names with whitespaces should be quoted or escaped.
 #
 # (Continued example:)
-# namelist=("X session" Console FBTerm "Sub menu")
+# namelist=('X session' Console FBTerm 'Sub menu')
 
 # Type of the programs, one-by-one matched with $binlist.
 # `C' for *C*onsole programs, which would be `exec'ed.
@@ -39,19 +39,20 @@ countfrom=0
 display=0
 
 # Where should the first X tty be spawned?
-# special value 'keep' causes to run X in current tty
+# special value `keep' causes to run X in current tty.
 xtty=7
 
 # Should cdm(1) stick to the specified display?
 locktty=no
 
-# Additional arguments to pass to X server, which is usually called as:
-#   /usr/bin/X :$display $serverargs vt$((xtty+display))
-serverargs='-nolisten tcp'
-
 # Use ConsoleKit for X session?
 consolekit=yes
 
 # Timeout for waiting for X session to register with ConsoleKit.
 cktimeout=30
 
+# Additional arguments to pass to X server, which is usually called as:
+#   /usr/bin/X :$display "${serverargs[@]}" vt$((xtty+display))
+# Arguments with whitespaces should be quoted or escaped.
+serverargs=(-nolisten tcp)
+
diff --git a/src/profile.sh b/src/profile.sh
index c5eae0a..3dbdeac 100644
--- a/src/profile.sh
+++ b/src/profile.sh
@@ -1,5 +1,8 @@
-if [[ "$(tty)" == /dev/tty* ]]; then
+# To avoid potential situation where cdm(1) crashes on every TTY, here we
+# default to execute cdm(1) on tty1 only, and leave other TTYs untouched.
+if [[ "$(tty)" == '/dev/tty1' ]]; then
     [[ -n "$CDM_SPAWN" ]] && return
-    [[ -z "$DISPLAY$SSH_TTY" ]] && exec cdm
+    # Avoid executing cdm(1) when X11 has already been started.
+    [[ -z "$DISPLAY$SSH_TTY$(pgrep xinit)" ]] && exec cdm
 fi