Code quality upgrade

This is what you get when Dave Reisner points you at some bash anti-patterns.
Also in this commit:
- updated documentation
- bugfix revision of the IPv6 SLAAC address/route bug

22 files changed, 146 insertions, 144 deletions

diff --git a/docs/netcfg-profiles.txt b/docs/netcfg-profiles.txt
index 2aa7653..1c666bc 100644
--- a/docs/netcfg-profiles.txt
+++ b/docs/netcfg-profiles.txt
@@ -1,7 +1,8 @@
-% NETCFG-PROFILES(5) netcfg 2.6.8 | Arch Linux
-% Rémy Oudompheng <remy@archlinux.org>
+% NETCFG-PROFILES(5) netcfg 2.7 | Arch Linux
+% Jouke Witteveen <j.witteveen@gmail.com>
+  Rémy Oudompheng <remy@archlinux.org>
   James Rayner <james@archlinux.org>
-% 14 August 2011
+% 29 February 2012
 
 NAME
 ====
@@ -56,6 +57,8 @@ openvpn
 :   OpenVPN setup.
 ppp
 :   PPP connections setup.
+pppoe
+:   PPPoE connections setup.
 
 The configuration variable for these connection types is described in the
 following sections.
diff --git a/docs/netcfg.txt b/docs/netcfg.txt
index 0cb4408..499219f 100644
--- a/docs/netcfg.txt
+++ b/docs/netcfg.txt
@@ -1,7 +1,8 @@
-% NETCFG(8) netcfg 2.6.8 | Arch Linux
-% Rémy Oudompheng <remy@archlinux.org>
+% NETCFG(8) netcfg 2.7 | Arch Linux
+% Jouke Witteveen <j.witteveen@gmail.com>
+  Rémy Oudompheng <remy@archlinux.org>
   James Rayner <james@archlinux.org>
-% 2011-08-14
+% 2012-02-29
 
 NAME
 ====
@@ -37,12 +38,12 @@ current
 :   Report currently running profiles
 `-c`, check-iface *profile*
 :   Start the specified profile, only if it's interface is not currently up.
-
 `-u`, up *profile*
 :   Start the specified profile
 `-r`, reconnect *profile*
 :   Disconnect and reconnect the specified profile
-
+`-R`, iface-recon *interface*
+:   Reconnect profile active on specified interface
 `-d`, down *profile*
 :   Stop the specified profile
 `-i`, iface-down *interface*
diff --git a/rc.d/net-auto-wired b/rc.d/net-auto-wired
index 21f487d..859e57d 100755
--- a/rc.d/net-auto-wired
+++ b/rc.d/net-auto-wired
@@ -8,9 +8,9 @@
 if [[ ! -x /usr/sbin/ifplugd ]]; then
    echo "Please install 'ifplugd' to use net-auto-wired"
    exit 1
-fi  
+fi
 
-if [ -z "${WIRED_INTERFACE}" ]; then
+if [[ -z "${WIRED_INTERFACE}" ]]; then
   echo "No interface name set. Add to /etc/conf.d/netcfg a line"
   echo "  WIRED_INTERFACE=\"your_interface\""
   exit 1
@@ -19,7 +19,7 @@ fi
 CFG=/etc/ifplugd/ifplugd.conf
 ACTION=/etc/ifplugd/netcfg.action
 PIDFILE=/var/run/ifplugd.$WIRED_INTERFACE.pid
-[[ -f $PIDFILE ]] && PID=$(cat $PIDFILE)
+[[ -f $PIDFILE ]] && read PID < $PIDFILE
 
 # Source ifplugd configuration
 [ -f $CFG ] && . $CFG
@@ -31,8 +31,8 @@ case "$1" in
     fi
     stat_busy "Starting netcfg auto-wired mode for interface ${WIRED_INTERFACE}"
     A="`eval echo \$\{ARGS_${WIRED_INTERFACE}\}`"
-    [ -z "$A" ] && A="$ARGS"
-    [ -z "$PID" ] && /usr/sbin/ifplugd -i $WIRED_INTERFACE -r $ACTION $A
+    [[ "$A" ]] || A="$ARGS"
+    [[ "$PID" ]] || /usr/sbin/ifplugd -i $WIRED_INTERFACE -r $ACTION $A
     # ifplugd may return non-zero, but still succeed if -w is passed, as default in upstream config.
     sleep 1
     if [[ -f $PIDFILE ]]; then
@@ -45,8 +45,7 @@ case "$1" in
   stop)
     if ! ck_daemon net-auto-wired; then
       stat_busy "Stopping netcfg auto-wired mode for interface ${WIRED_INTERFACE}"
-      [ -n "$PID" ] && /usr/sbin/ifplugd -k -i $WIRED_INTERFACE -r $ACTION
-      if [ $? -eq 0 ]; then
+      if [[ "$PID" ]] && /usr/sbin/ifplugd -k -i $WIRED_INTERFACE -r $ACTION; then
         rm_daemon net-auto-wired
         stat_done
       else
@@ -60,6 +59,6 @@ case "$1" in
     "$0" start
     ;;
   *)
-    echo "Usage: $0 {start|stop|restart}"  
+    echo "Usage: $0 {start|stop|restart}"
 esac
 exit 0
diff --git a/rc.d/net-auto-wireless b/rc.d/net-auto-wireless
index a03097b..79c43b0 100755
--- a/rc.d/net-auto-wireless
+++ b/rc.d/net-auto-wireless
@@ -10,7 +10,7 @@ if [[ ! -x /usr/sbin/wpa_actiond ]]; then
    exit 1
 fi
 
-if [ -z "${WIRELESS_INTERFACE}" ]; then
+if [[ -z "${WIRELESS_INTERFACE}" ]]; then
     echo "No interface name set. Add to /etc/conf.d/netcfg a line"
     echo "  WIRELESS_INTERFACE=\"your_interface\""
     exit 1
@@ -31,8 +31,7 @@ case "$1" in
         done
 
         stat_busy "Starting netcfg auto-wireless mode for interface ${WIRELESS_INTERFACE}"
-        /usr/bin/netcfg-wpa_actiond "${WIRELESS_INTERFACE}" >/dev/null
-        if [ $? -eq 0 ]; then
+        if /usr/bin/netcfg-wpa_actiond "${WIRELESS_INTERFACE}" >/dev/null; then
             add_daemon net-auto-wireless
             stat_done
         else
@@ -42,8 +41,7 @@ case "$1" in
     stop)
         if ! ck_daemon net-auto-wireless; then
             stat_busy "Stopping netcfg auto-wireless mode for interface ${WIRELESS_INTERFACE}"
-            /usr/bin/netcfg-wpa_actiond stop "${WIRELESS_INTERFACE}" >/dev/null
-            if [ $? -eq 0 ]; then
+            if /usr/bin/netcfg-wpa_actiond stop "${WIRELESS_INTERFACE}" >/dev/null; then
                 rm_daemon net-auto-wireless
                 stat_done
             else
diff --git a/rc.d/net-profiles b/rc.d/net-profiles
index f7770ee..e8b8bc7 100755
--- a/rc.d/net-profiles
+++ b/rc.d/net-profiles
@@ -70,9 +70,9 @@ case "$1" in
 
         # shutdown any profiles started by netcfg (or from NET_PROFILES in rc.conf)
         # JP: only attempt to disconnect the profiles _this daemon_ was told to control
-        for profile in $(cat "$STATE_DIR/net-profiles"); do
+        while read profile; do
             /usr/bin/netcfg2 down "$profile"
-        done
+        done < "$STATE_DIR/net-profiles"
         rm -f "$STATE_DIR/net-profiles"
         rm_daemon net-profiles
         ;;
diff --git a/scripts/ifplugd.action b/scripts/ifplugd.action
index 602e61a..573131d 100644
--- a/scripts/ifplugd.action
+++ b/scripts/ifplugd.action
@@ -1,6 +1,6 @@
 #!/bin/bash
 #
-# ifplugd.action script for netcfg 
+# ifplugd.action script for netcfg
 
 . /etc/rc.conf
 . /etc/rc.d/functions
@@ -10,8 +10,8 @@ shopt -s extglob
 case "$2" in
   up)
     # Look for a dhcp based profile to try first
-    # dhcp can actually outright fail, whereas 
-    # it's difficult to tell if static succeeded 
+    # dhcp can actually outright fail, whereas
+    # it's difficult to tell if static succeeded
     # Also check profile is same iface and is right connection
     echo "up"
     declare -a preferred_profiles
@@ -49,6 +49,6 @@ case "$2" in
   *)
     echo "Wrong arguments" > /dev/stderr
   ;;
-esac  
+esac
 
 exit 1
diff --git a/scripts/netcfg-menu b/scripts/netcfg-menu
index ff57005..f7c9019 100755
--- a/scripts/netcfg-menu
+++ b/scripts/netcfg-menu
@@ -5,7 +5,7 @@
 if [[ ! -x /usr/bin/dialog ]]; then
    echo "Please install 'dialog' to use netcfg-menu"
    exit 1
-fi  
+fi
 
 check_make_state_dir
 
@@ -18,10 +18,8 @@ i=0
 while read prof; do
     # if there is a profile called "main", Use as default
     [[ "$prof" = "main" ]] && DEFAULT="main"
-    profiles[$i]="$prof"
-    let i++
-    profiles[$i]=$(. "$PROFILE_DIR/$prof"; echo "$DESCRIPTION")
-    let i++
+    profiles[i++]="$prof"
+    profiles[i++]=$(. "$PROFILE_DIR/$prof"; echo "$DESCRIPTION")
 done < <(list_profiles | sort)  # JP: re-use list_profiles instead of duplicating it; avoid subshell we'd get by piping it to the while read...
 
 if [[ ${#profiles} -eq 0 ]]; then
@@ -52,12 +50,12 @@ case $ret in
     255) # timeout - use default
         profile_up "$DEFAULT"       # JP: use profile_up and catch $?
         ret=$?
-        if [[ $ret -eq 0 ]]; then echo "$DEFAULT" > "$STATE_DIR/menu"; fi
+        (( ret == 0 )) && echo "$DEFAULT" > "$STATE_DIR/menu"
         ;;
     0)  # User selection
         profile_up "$(cat "$ANSWER")"
         ret=$?
-        if [[ $ret -eq 0 ]]; then mv "$ANSWER" "$STATE_DIR/menu"; fi
+        (( ret == 0 )) && mv "$ANSWER" "$STATE_DIR/menu"
         ;;
     *)  # Shouldnt happen
         exit_err "Abnormal ret code from dialog: $ret"
diff --git a/scripts/netcfg-wpa_actiond b/scripts/netcfg-wpa_actiond
index 2e402df..c8a2867 100755
--- a/scripts/netcfg-wpa_actiond
+++ b/scripts/netcfg-wpa_actiond
@@ -43,11 +43,11 @@ fi
 [[ -f "$IFACE_DIR/$interface" ]] && source "$IFACE_DIR/$interface"
 
 if [[ -f "$CONN_DIR/interfaces/$interface" ]]; then
-    netcfg -i $interface
+    netcfg -i "$interface"
 fi
 
 if [[ -n "$RFKILL" ]]; then # Enable radio if necessary
-    enable_rf $interface $RFKILL $RFKILL_NAME || exit $?
+    enable_rf "$interface" "$RFKILL" "$RFKILL_NAME" || exit $?
 fi
 
 WPA_CONF="$(make_wpa_config_file $interface)"
@@ -65,9 +65,9 @@ fi | while read profile; do
     [[ $INTERFACE != $interface ]] && exit 1
     # Exclude wpa-config, the wpa_conf is 'complete' and doesn't fit in this scheme
     [[ -z "$SECURITY" ]] && SECURITY="none"
-    [[ $SECURITY == "wpa-config" ]] && exit 1 
-    
-    echo -e "network={ \n$(make_wpa_config) \nid_str=\"$profile\" \n}" >> $WPA_CONF
+    [[ $SECURITY == "wpa-config" ]] && exit 1
+
+    printf "%s\n" "network={" "$(make_wpa_config)" "id_str=\"$profile\"" "}" >> $WPA_CONF
     )
 done
 
diff --git a/scripts/wifi-menu b/scripts/wifi-menu
index fc21a9b..25ac87e 100755
--- a/scripts/wifi-menu
+++ b/scripts/wifi-menu
@@ -46,12 +46,12 @@ init_profiles()
         )
         case $? in
             2)
-                GENERATED[${#GENERATED[@]}]="$profile"
+                GENERATED+=("$profile")
                 ;&
             1)
-                PROFILES[$i]="$profile"
-                ESSIDS[$i]="$essid"
-                let i++
+                PROFILES[i]=$profile
+                ESSIDS[i]=$essid
+                (( ++i ))
                 ;;
         esac
     done
@@ -60,29 +60,29 @@ init_profiles()
 # Builds ENTRIES as an argument list for dialog based on scan results in $1.
 init_entries()
 {
-    local i=0 flags security signal ssid
+    local i=0 flags signal ssid
     while IFS=$'\t' read signal flags ssid; do
-        ENTRIES[$i]="--"  # $ssid might look like an option to dialog.
-        let i++
-        ENTRIES[$i]="$ssid"
-        let i++
+        ENTRIES[i++]="--"  # $ssid might look like an option to dialog.
+        ENTRIES[i++]=$ssid
         if inarray "$ssid" "${ESSIDS[@]}"; then
             if inarray "$(ssid_to_profile "$ssid")" "${GENERATED[@]}"; then
-                ENTRIES[$i]="+"  # Automatically generated
+                ENTRIES[i]="+"  # Automatically generated
             else
-                ENTRIES[$i]="*"  # Handmade
+                ENTRIES[i]="*"  # Handmade
             fi
         else
-            ENTRIES[$i]="-"  # Not present
+            ENTRIES[i]="-"  # Not present
         fi
         if [[ "$ssid" = "$CONNECTION" ]]; then
-            ENTRIES[$i]="!"  # Currently connected
+            ENTRIES[i]="!"  # Currently connected
         fi
-        security="$(expr match "$flags" ".*\(WPA2\|WPA\|WEP\)")"
-        : ${security:="NONE"}
-        ENTRIES[$i]+=":${security,,}"
-        ENTRIES[$i]+="   :$signal"
-        let i++
+        if [[ "$flags" =~ WPA2|WPA|WEP ]]; then
+            ENTRIES[i]+=":${BASH_REMATCH[0],,}"
+        else
+            ENTRIES[i]+=":none"
+        fi
+        ENTRIES[i]+="   :$signal"
+        (( ++i ))
     done < "$1"
 }
 
@@ -91,8 +91,8 @@ ssid_to_profile()
 {
     local i
     for i in $(seq 0 $((${#ESSIDS[@]}-1))); do
-        if [[ "$1" = "${ESSIDS[$i]}" ]]; then
-            printf "%s" "${PROFILES[$i]}"
+        if [[ "$1" = "${ESSIDS[i]}" ]]; then
+            printf "%s" "${PROFILES[i]}"
             return 0
         fi
     done
@@ -105,10 +105,13 @@ create_profile()
     local flags key msg security
     PROFILE="$INTERFACE-$1"
     [[ -f "$PROFILE_DIR/$PROFILE" ]] && PROFILE+=".wifi-menu"
-    flags="$(grep -m 1 $'\t'"$1\$" "$NETWORKS" | cut -f 2)"
-    security="$(expr match "$flags" ".*\(WPA\|WEP\)")"
-    : ${security:="NONE"}
-    if [[ "$flags" =~ "PSK"|"WEP" ]]; then
+    flags=$(grep -m 1 $'\t'"$1\$" "$NETWORKS" | cut -f 2)
+    if [[ "$flags" =~ WPA|WEP ]]; then
+        security=${BASH_REMATCH[0],,}
+    else
+        security=none
+    fi
+    if [[ "$flags" =~ PSK|WEP ]]; then
         msg="Enter $security security key for\n'$1'"
         if [[ "$OBSCURE" ]]; then
             key=$(wpa_passphrase "$1" "$(dialog --insecure --passwordbox \
@@ -120,13 +123,13 @@ create_profile()
             key="KEY='$(dialog --inputbox "$msg" 10 40 --stdout)'"
             RETURN=$?
         fi
-        [[ $RETURN -eq 0 ]] || return $RETURN
+        (( RETURN == 0 )) || return $RETURN
     fi
     cat << EOF > "$PROFILE_DIR/$PROFILE" || return 4
 CONNECTION='wireless'
 DESCRIPTION='Automatically generated profile by wifi-menu'
 INTERFACE='$INTERFACE'
-SECURITY='${security,,}'
+SECURITY='$security'
 ESSID='$1'
 IP='dhcp'
 $key
@@ -147,12 +150,12 @@ connect_to_ssid()
     else
         PROFILE=$(create_profile "$1")
         RETURN=$?
-        [[ $RETURN -eq 0 ]] || return $RETURN
+        (( RETURN == 0 )) || return $RETURN
         SPAWNED_PROFILE=1
         clear
     fi
     if ! profile_up "$PROFILE"; then
-        if [[ "$SPAWNED_PROFILE" ]]; then
+        if (( SPAWNED_PROFILE )); then
             msg="         CONNECTING FAILED
 
 Do you want to keep the generated profile ('$PROFILE')?"
@@ -191,7 +194,7 @@ if [[ $(id -u) -ne 0 ]]; then
     exit_stderr "This script needs to be run with root privileges"
 fi
 
-INTERFACE="${1-$WIRELESS_INTERFACE}"
+INTERFACE=${1-$WIRELESS_INTERFACE}
 if [[ -z "$INTERFACE" ]]; then
     report_err "Missing interface specification"
     usage
@@ -200,16 +203,16 @@ fi
 
 cd /  # We do not want to spawn anything that can block unmounting
 is_interface "$INTERFACE" || exit_fail "No such interface: $INTERFACE"
-if [[ -z "$(ip link show up dev $INTERFACE)" ]]; then
+if [[ -z "$(ip link show up dev "$INTERFACE" 2> /dev/null)" ]]; then
     [[ -f "$IFACE_DIR/$INTERFACE" ]] && . "$IFACE_DIR/$INTERFACE"
     bring_interface up "$INTERFACE" || exit_fail "Interface unavailable"
     SPAWNED_INTERFACE=1
 fi
 
 report_try "Scanning for networks"
-CONNECTION=$(expr substr \
-                  "$(wpa_cli -p "$WPA_CTRL_PATH" -i "$INTERFACE" status \
-                         2> /dev/null | grep "^ssid=")" 6 32)
+CONNECTION=$(wpa_cli -p "$WPA_CTRL_PATH" -i "$INTERFACE" status 2> /dev/null \
+                 | grep "^ssid=")
+CONNECTION=${CONNECTION#ssid=}
 init_profiles "$INTERFACE"
 NETWORKS=$(wpa_supplicant_scan_info "$INTERFACE" 3,4,5)
 [[ $? -eq 0 ]] && init_entries "$NETWORKS"
@@ -227,7 +230,7 @@ Flags description:
     CHOICE=$(dialog --column-separator : --menu "$MSG" 24 50 12 \
                  "${ENTRIES[@]}" --stdout)
     RETURN=$?
-    if [[ $RETURN -eq 0 ]]; then
+    if (( RETURN == 0 )); then
         connect_to_ssid "$CHOICE"
         RETURN=$?
     fi
@@ -256,5 +259,5 @@ case $RETURN in
         ;;
 esac
 [[ -f "$NETWORKS" ]] && rm -f "$NETWORKS"
-[[ $RETURN -ne 0 && "$SPAWNED_INTERFACE" ]] && bring_interface down "$INTERFACE"
+(( RETURN && SPAWNED_INTERFACE )) && bring_interface down "$INTERFACE"
 exit $RETURN
diff --git a/src-wireless/net-auto b/src-wireless/net-auto
index ca52b3e..5f972c3 100644
--- a/src-wireless/net-auto
+++ b/src-wireless/net-auto
@@ -35,9 +35,9 @@ case "$1" in
             exit_stderr "net-auto not running"
         fi
 
-        for iface in $(cat "$STATE_DIR/net-auto"); do
+        while read iface; do
             /usr/bin/netcfg2 iface-down "$iface"
-        done
+        done < "$STATE_DIR/net-auto"
         rm -f "$STATE_DIR/net-auto"
         rm_daemon net-auto
         ;;
diff --git a/src-wireless/netcfg-auto-wireless b/src-wireless/netcfg-auto-wireless
index a3e3fb9..4d0a5e1 100644
--- a/src-wireless/netcfg-auto-wireless
+++ b/src-wireless/netcfg-auto-wireless
@@ -19,7 +19,7 @@ wifi_auto()
         set_rf_state "$interface" up || exit $?
     fi
 
-    bring_interface up "$interface" # uses iproute methods---is it there any value to providing option to use ifconfig?
+    bring_interface up "$interface"  # uses iproute methods - is there an option to use ifconfig?
     networks=$(list_networks "$interface")
 
     if [[ -z "$networks" ]]; then
@@ -31,7 +31,7 @@ wifi_auto()
 
     local found_profile
 
-    [ -z "$AUTO_PROFILES" ] && AUTO_PROFILES=$(list_profiles)
+    [[ "$AUTO_PROFILES" ]] || AUTO_PROFILES=$(list_profiles)
 
     # JP: add ability to use AP instead of ESSID
     while read ap essid; do
diff --git a/src-wireless/wireless-dbus b/src-wireless/wireless-dbus
index 0e219b6..f3773ee 100644
--- a/src-wireless/wireless-dbus
+++ b/src-wireless/wireless-dbus
@@ -35,7 +35,7 @@ def read_config(config):
 def wep_hex2dec(key):
     if len(key) not in [10, 26]:
         fail("Bad key", report_type="err")
-    
+
     x=0
     new_key=[]
     while x<len(key):
@@ -76,7 +76,7 @@ def start(profile, essid):
 
     # Base arguments
     args=["wpa_supplicant", "-Bu", "-P/run/wpa_supplicant.pid"]
-    
+
     try:
         args.append(profile['WPA_OPTS'])
     except KeyError:
@@ -103,7 +103,7 @@ def start(profile, essid):
     bus = dbus.SystemBus()
     wpas_obj = bus.get_object(WPAS_DBUS_SERVICE, WPAS_DBUS_OPATH)
     wpas = dbus.Interface(wpas_obj, WPAS_DBUS_INTERFACE)
-   
+
     # Add/Get interface path
     try:
         driver=profile["WPA_DRIVER"]
@@ -117,12 +117,12 @@ def start(profile, essid):
 
     # Get interface object
     if_obj = bus.get_object(WPAS_DBUS_SERVICE, path)
-    iface = dbus.Interface(if_obj, WPAS_DBUS_INTERFACES_INTERFACE);  
-    
+    iface = dbus.Interface(if_obj, WPAS_DBUS_INTERFACES_INTERFACE);
+
     # Add and select the network. Networks already specified for wpa-config
     if profile['SECURITY'] in ['wpa','wep','none']:
         report('debug', 'wireless_dbus', 'add and select network')
-        
+
         path = iface.addNetwork()
         net_obj = bus.get_object(WPAS_DBUS_SERVICE, path)
         rnet = dbus.Interface(net_obj, WPAS_DBUS_NETWORKS_INTERFACE)
@@ -132,8 +132,8 @@ def start(profile, essid):
         essid = profile["ESSID"]
 
     if profile['SECURITY'] == "wpa":
-        opts = dbus.Dictionary({"ssid": dbus.ByteArray(essid), 
-                                "psk": dbus.String(profile['KEY'])}, 
+        opts = dbus.Dictionary({"ssid": dbus.ByteArray(essid),
+                                "psk": dbus.String(profile['KEY'])},
                                signature="sv")
         report('debug', 'wireless_dbus', 'connect to network with security=wpa')
         rnet.set(opts)
@@ -141,7 +141,7 @@ def start(profile, essid):
         key=profile['KEY']
         if key[:2] == "s:": # String key prefixed by "s:"
             keydbus=key[2:]
-        else: # Hex key 
+        else: # Hex key
             key=wep_hex2dec(key)
             keydbus = dbus.ByteArray()
             for l in key:
@@ -155,11 +155,11 @@ def start(profile, essid):
         report('debug', 'wireless_dbus', 'connect to network with security=wep')
         rnet.set(opts)
     elif profile['SECURITY'] == "none":
-        opts = dbus.Dictionary({"ssid": dbus.ByteArray(essid)}, 
+        opts = dbus.Dictionary({"ssid": dbus.ByteArray(essid)},
                                signature="sv")
         report('debug', 'wireless_dbus', 'connect to network with security=none')
         rnet.set(opts)
-       
+
     # Determine timeout
     try:
         timeout = int(profile["TIMEOUT"])
@@ -174,7 +174,7 @@ def start(profile, essid):
         state = iface.state()
         if state == "COMPLETED":
             break
-        
+
         if n == timeout:
             fail("Association/Authentication failed:" + state)
 
@@ -184,7 +184,7 @@ def start(profile, essid):
     except subprocess.CalledProcessError:
         fail()
     sys.exit(0)
-  
+
 def stop(profile):
     ret = subprocess.call([ETHERNET_IPROUTE, "down", sys.argv[2]])
     os.kill(int(open("/run/wpa_supplicant.pid").read()),SIGTERM)
diff --git a/src/8021x b/src/8021x
index 13c5b6e..560a44d 100644
--- a/src/8021x
+++ b/src/8021x
@@ -16,7 +16,7 @@ wpa_check()
         [[ "$wpa_state" = "$CONDITION" ]]
         ) && return 0
         sleep 1
-        let timeout++
+        (( ++timeout ))
     done
     echo "$wpa_state"
     # wpa_cli -i "$INTERFACE" terminate >/dev/null 2>&1   # callers sometimes called stop_wpa, which does more but seems redundant
@@ -178,9 +178,9 @@ make_wpa_config_file() {
 
     # make empty tmp dir with correct permissions, rename it
     check_make_state_dir
-    # create symlink for old compatibility
+    # create symlink for old compatibility (Jouke: is this still needed?)
     mkdir -p /run/wpa_supplicant
-    if [ ! -e /var/run/wpa_supplicant ]; then
+    if [[ ! -e /var/run/wpa_supplicant ]]; then
         ln -s /run/wpa_supplicant /var/run
     fi
     rm -rf "$WPA_CONF"
@@ -237,10 +237,11 @@ make_wpa_config() {
         echo "key_mgmt=NONE"
         ;;
     wpa)
+        echo "proto=RSN WPA"
         if [[ "${#KEY}" -eq 64 ]]; then
-            echo "proto=RSN WPA\npsk=$KEY"
+            echo "psk=$KEY"
         else
-            echo "proto=RSN WPA\npsk=\"$KEY\""
+            echo "psk=\"$KEY\""
         fi
         ;;
     esac
diff --git a/src/connections/bond b/src/connections/bond
index ea6af77..132225a 100644
--- a/src/connections/bond
+++ b/src/connections/bond
@@ -5,7 +5,7 @@ IFENSLAVE="/sbin/ifenslave"
 bond_up() {
     load_profile "$1"
 
-    if [ -e /sys/class/net/$INTERFACE ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
         report_fail "Interface $INTERFACE already exists."
         exit 1
     else
@@ -31,12 +31,12 @@ bond_down() {
 
     "$CONN_DIR/ethernet" down "$1"
     bring_interface down "$INTERFACE"
-    ip link delete $INTERFACE &>/dev/null
+    ip link delete "$INTERFACE" &> /dev/null
     return 0
 }
 
 bond_status() {
-    if [ -e /sys/class/net/$INTERFACE ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
         return 0
     else
         return 1
diff --git a/src/connections/bridge b/src/connections/bridge
index 3cf60c1..e134647 100644
--- a/src/connections/bridge
+++ b/src/connections/bridge
@@ -6,27 +6,23 @@ bridge_up() {
     local bridge_interface
     load_profile "$1"
 
-    if [ -e "/sys/class/net/$INTERFACE" ]; then
-        if [ ! -d "/sys/class/net/$INTERFACE/brif" ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
+        if [[ ! -d "/sys/class/net/$INTERFACE/brif" ]]; then
             report_fail "Interface $INTERFACE already exists and is not a bridge."
             exit 1
         fi
     else
-        $BRCTL addbr $INTERFACE
+        $BRCTL addbr "$INTERFACE"
     fi
 
     for bridge_client in $BRIDGE_INTERFACES; do
-      ip link set $bridge_client promisc on up
-      ip addr flush dev $bridge_client
-      $BRCTL addif $INTERFACE $bridge_client
+      ip link set "$bridge_client" promisc on up
+      ip addr flush dev "$bridge_client"
+      $BRCTL addif "$INTERFACE" "$bridge_client"
     done
     # Set options
-    if [ -n "$FWD_DELAY" ]; then
-        $BRCTL setfd $INTERFACE "$FWD_DELAY"
-    fi
-    if [ -n "$MAX_AGE" ]; then
-        $BRCTL setmaxage $INTERFACE "$MAX_AGE"
-    fi
+    [[ "$FWD_DELAY" ]] && $BRCTL setfd "$INTERFACE" "$FWD_DELAY"
+    [[ "$MAX_AGE" ]] && $BRCTL setmaxage "$INTERFACE" "$MAX_AGE"
 
     bring_interface up "$INTERFACE"
     "$CONN_DIR/ethernet" up "$1"
@@ -38,14 +34,14 @@ bridge_down() {
     load_profile "$1"
 
     for bridge_client in $BRIDGE_INTERFACES; do
-      ip link set $bridge_client promisc off down
-      $BRCTL delif $INTERFACE $bridge_client
+      ip link set "$bridge_client" promisc off down
+      $BRCTL delif "$INTERFACE" "$bridge_client"
     done
 
     "$CONN_DIR/ethernet" down "$1"
     bring_interface down "$INTERFACE"
-    $BRCTL delbr $INTERFACE
-    return 0 
+    $BRCTL delbr "$INTERFACE"
+    return 0
 }
 
 # Returns status of profile - is it still functional?
diff --git a/src/connections/ethernet b/src/connections/ethernet
index 78f8240..8be3c6f 100644
--- a/src/connections/ethernet
+++ b/src/connections/ethernet
@@ -23,8 +23,8 @@ ethernet_up() {
     fi
 
     # Disable IPv6 before the interface to prevent SLAAC
-    if [[ "$IP6" == "no"]]; then
-        sysctl -q -w net.ipv6.conf.$INTERFACE.disable_ipv6=1
+    if [[ "$IP6" == "no" ]]; then
+        sysctl -q -w "net.ipv6.conf.$INTERFACE.disable_ipv6=1"
     fi
 
     report_debug ethernet_iproute_up ifup
@@ -32,7 +32,8 @@ ethernet_up() {
 
 
     if ! checkyesno "${SKIPNOCARRIER:-no}" && ip link show dev "$INTERFACE" | fgrep -q "NO-CARRIER"; then
-        sleep ${CARRIER_TIMEOUT:-2} # Some cards are plain slow to come up. Don't fail immediately.
+        # Some cards are plain slow to come up. Don't fail immediately.
+        sleep ${CARRIER_TIMEOUT:-2}
         if ip link show dev "$INTERFACE" | fgrep -q "NO-CARRIER"; then
             report_iproute "No connection"
         fi
@@ -47,7 +48,7 @@ ethernet_up() {
         if grep "^ *ctrl_interface=" "$WPA_CONF" &>/dev/null; then
             WPA_CTRL_PATH=$(grep -m 1 "^ *ctrl_interface=" "$WPA_CONF" | tail -n 1 | cut -d= -f 2- | sed -r 's/DIR=(.*) +GROUP=.*/\1/')
         fi
- 
+
         report_debug ethernet_iproute_up start_wpa "$INTERFACE" "$WPA_CONF" "$WPA_DRIVER" "$WPA_OPTS"
         if ! start_wpa "$INTERFACE" "$WPA_CONF" "$WPA_DRIVER" "$WPA_OPTS"; then
             report_fail "wpa_supplicant did not start, possible configuration error"
@@ -94,7 +95,7 @@ ethernet_up() {
     static)
         if [[ -n "$ADDR" ]]; then
             [[ -z $NETMASK ]] && NETMASK=24
-            report_debug ethernet_iproute_up ip addr add "$ADDR/$NETMASK" brd + dev "$INTERFACE" 
+            report_debug ethernet_iproute_up ip addr add "$ADDR/$NETMASK" brd + dev "$INTERFACE"
             if ! ip addr add "$ADDR/$NETMASK" brd + dev "$INTERFACE"; then
                 report_iproute "Could not configure interface"
             fi
@@ -140,10 +141,12 @@ ethernet_up() {
     # Load ipv6 module if necessary (FS#25530)
     case "$IP6" in
     dhcp*|stateless|static)
-        [ -d "/proc/sys/net/ipv6" ] || modprobe ipv6
+        [[ -d "/proc/sys/net/ipv6" ]] || modprobe ipv6
         ;;
     no)
-        [ -d /proc/sys/net/ipv6 ] && sysctl -q -w net.ipv6.conf.$INTERFACE.accept_ra=0
+        [[ -d "/proc/sys/net/ipv6" ]] && sysctl -q -w "net.ipv6.conf.$INTERFACE.accept_ra=0"
+        ;;
+    "")  # undefined IP6 does not prevent RA's from being received -> nop
         ;;
     *)
         report_iproute "IP6 must be 'dhcp', 'dhcp-noaddr', 'stateless', 'static' or 'no'"
@@ -153,12 +156,12 @@ ethernet_up() {
     case "$IP6" in
     dhcp*)
         if [[ -x /usr/sbin/dhclient ]]; then
-            _DHCLIENT_PIDFILE=/run/dhclient6-${INTERFACE}.pid
+            _DHCLIENT_PIDFILE="/run/dhclient6-${INTERFACE}.pid"
             if [[ "$IP6" = "dhcp-noaddr" ]]; then
-                sysctl -q -w net.ipv6.conf.$INTERFACE.accept_ra=1
+                sysctl -q -w "net.ipv6.conf.$INTERFACE.accept_ra=1"
                 DHCLIENT6_OPTIONS="-S ${DHCLIENT6_OPTIONS}"
             else
-                sysctl -q -w net.ipv6.conf.$INTERFACE.accept_ra=0
+                sysctl -q -w "net.ipv6.conf.$INTERFACE.accept_ra=0"
             fi
             rm -r ${_DHCLIENT_PIDFILE} &>/dev/null
             report_debug ethernet_up dhclient -6 -q -e TIMEOUT="${DHCP_TIMEOUT:-10}" -pf ${_DHCLIENT_PIDFILE} "$INTERFACE"
@@ -172,10 +175,10 @@ ethernet_up() {
         fi
         ;;
     stateless)
-        sysctl -q -w net.ipv6.conf.$INTERFACE.accept_ra=1
+        sysctl -q -w "net.ipv6.conf.$INTERFACE.accept_ra=1"
         ;;
     static)
-        sysctl -q -w net.ipv6.conf.$INTERFACE.accept_ra=0
+        sysctl -q -w "net.ipv6.conf.$INTERFACE.accept_ra=0"
         if [[ -n "$ADDR6" ]]; then
             for addr in "${ADDR6[@]}"; do
                 report_debug ethernet_iproute_up ip -6 addr add "$addr" dev "$INTERFACE"
@@ -194,8 +197,8 @@ ethernet_up() {
         # Add static IPv6 routes
         if [[ -n "$ROUTES6" ]]; then
             for route in "${ROUTES6[@]}"; do
-            report_debug ethernet_iproute_up ip -6 route add $route dev $INTERFACE
-                if ! ip -6 route add $route dev $INTERFACE ; then
+            report_debug ethernet_iproute_up ip -6 route add "$route" dev "$INTERFACE"
+                if ! ip -6 route add "$route" dev "$INTERFACE"; then
                     report_iproute "Adding route '$route' failed"
                 fi
             done
@@ -267,7 +270,7 @@ ethernet_down() {
     else
         bring_interface down "$INTERFACE"
     fi
-    return 0 
+    return 0
 }
 
 # Returns status of profile - is it still functional?
@@ -277,7 +280,7 @@ ethernet_status() {
     fi
 }
 
-# Stop wpa_supplicant if neccessary 
+# Stop wpa_supplicant if neccessary
 stop_80211x() {
     if checkyesno "${AUTH8021X:-no}"; then
         . "$SUBR_DIR/8021x"
diff --git a/src/connections/pppoe b/src/connections/pppoe
index 07eb9ae..ba9f67a 100644
--- a/src/connections/pppoe
+++ b/src/connections/pppoe
@@ -61,8 +61,8 @@ pppoe_down() {
     PIDFILE="/var/run/ppp-$1.pid"
 
     if [[ -e $PIDFILE ]]; then
-        PID=$(cat "$PIDFILE")
-        [[ -n "$PID" ]] && kill "$PID"
+        read PID < "$PIDFILE"
+        [[ "$PID" ]] && kill "$PID"
     fi
 
     rm "${cfg}"
diff --git a/src/connections/tunnel b/src/connections/tunnel
index 613cc67..67c7d9d 100644
--- a/src/connections/tunnel
+++ b/src/connections/tunnel
@@ -4,7 +4,7 @@
 tunnel_up() {
     load_profile "$1"
 
-    if [ -e "/sys/class/net/$INTERFACE" ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
         report_fail "Interface $INTERFACE already exists."
         exit 1
     else
diff --git a/src/connections/tuntap b/src/connections/tuntap
index 27641e4..84b3bce 100644
--- a/src/connections/tuntap
+++ b/src/connections/tuntap
@@ -4,7 +4,7 @@
 tuntap_up() {
     load_profile "$1"
 
-    if [ -e /sys/class/net/$INTERFACE ]; then
+    if [[ -e /sys/class/net/$INTERFACE ]]; then
         report_fail "Interface $INTERFACE already exists."
         exit 1
     else
@@ -26,7 +26,7 @@ tuntap_down() {
 }
 
 tuntap_status() {
-    if [ -e /sys/class/net/$INTERFACE ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
         return 0
     else
         return 1
diff --git a/src/connections/vlan b/src/connections/vlan
index 7b81e7f..97147c7 100644
--- a/src/connections/vlan
+++ b/src/connections/vlan
@@ -5,12 +5,12 @@ vlan_up() {
     local vlan_interface
     load_profile "$1"
 
-    if [ -e /sys/class/net/$INTERFACE ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
         report_fail "Interface $INTERFACE already exists."
         exit 1
     else
-        ip link set $VLAN_PHYS_DEV up
-        ip link add link $VLAN_PHYS_DEV name $INTERFACE type vlan id $VLAN_ID >/dev/null 2>&1
+        ip link set "$VLAN_PHYS_DEV" up
+        ip link add link "$VLAN_PHYS_DEV" name "$INTERFACE" type vlan id "$VLAN_ID" >/dev/null 2>&1
     fi
     bring_interface up "$INTERFACE"
     "$CONN_DIR/ethernet" up "$1"
@@ -23,12 +23,12 @@ vlan_down() {
 
     "$CONN_DIR/ethernet" down "$1"
     bring_interface down "$INTERFACE"
-    ip link delete $INTERFACE >/dev/null 2>&1
+    ip link delete "$INTERFACE" >/dev/null 2>&1
     return 0
 }
 
 vlan_status() {
-    if [ -e /sys/class/net/$INTERFACE ]; then
+    if [[ -e "/sys/class/net/$INTERFACE" ]]; then
         return 0
     else
         return 1
diff --git a/src/connections/wireless b/src/connections/wireless
index b19afde..f08ba43 100644
--- a/src/connections/wireless
+++ b/src/connections/wireless
@@ -27,7 +27,7 @@ wireless_up() {
 
     # Start wpa_supplicant
     WPA_CTRL_PATH=/run/wpa_supplicant
-    if [ "$SECURITY" = "wpa-config" ]; then
+    if [[ "$SECURITY" = "wpa-config" ]]; then
         WPA_CONF="${WPA_CONF:-/etc/wpa_supplicant.conf}"
         # Use defined control path (FS#24949)
         if grep "^ *ctrl_interface=" "$WPA_CONF" &>/dev/null; then
@@ -74,7 +74,7 @@ wireless_up() {
         wpa-config)
             ;;
         none|wep|wpa|wpa-configsection)
-            echo -e "network={ \n$(make_wpa_config) \n}" >> "$WPA_CONF"
+            printf "%s\n" "network={" "$(make_wpa_config)" "}" >> "$WPA_CONF"
             report_debug wireless_up "Configuration generated at $WPA_CONF"
             ;;
         *)
diff --git a/src/rfkill b/src/rfkill
index d61703d..4fbc34d 100644
--- a/src/rfkill
+++ b/src/rfkill
@@ -42,7 +42,7 @@ get_rf_state() {
     local INTERFACE="$1" PROFILE="$2" path state
 
     path=$(get_rf_path "$INTERFACE" "$RFKILL_NAME") || return 1
-    state=$(cat "$path/state")
+    read state < "$path/state"
 
     case "$state" in
         0|2)