[v2,6/7] fff-nodewatcher: fix shellcheck warnings

- SC2006: Use $(..) instead of deprecated `..`
- SC2086: Double quote to prevent globbing and word splitting.
- SC2046: Quote this to prevent word splitting.
- SC2012: Use find instead of ls to better handle non-alphanumeric filenames.
- SC2004: $ on variables in (( )) is unnecessary.
- SC2016: Expressions don't expand in single quotes, use double quotes for that.

Signed-off-by: Tim Niemeyer <tim@tn-x.org>
---

Changes in v2:
- Rebased with spaces
- Rebased on current master
- Removed empty line

 .../fff/fff-nodewatcher/files/usr/sbin/nodewatcher | 69 +++++++++++-----------
 1 file changed, 36 insertions(+), 33 deletions(-)

Reviewed-by: Jan Kraus <mayosemmel@gmail.com>

Am Samstag, den 11.06.2016, 17:20 +0200 schrieb Tim Niemeyer:
> - SC2006: Use $(..) instead of deprecated `..`
> - SC2086: Double quote to prevent globbing and word splitting.
> - SC2046: Quote this to prevent word splitting.
> - SC2012: Use find instead of ls to better handle non-alphanumeric filenames.
> - SC2004: $ on variables in (( )) is unnecessary.
> - SC2016: Expressions don't expand in single quotes, use double quotes for that.
> 
> Signed-off-by: Tim Niemeyer <tim@tn-x.org>
> ---
> 
> Changes in v2:
> - Rebased with spaces
> - Rebased on current master
> - Removed empty line
> 
>  .../fff/fff-nodewatcher/files/usr/sbin/nodewatcher | 69 +++++++++++-----------
>  1 file changed, 36 insertions(+), 33 deletions(-)
> 
> diff --git a/src/packages/fff/fff-nodewatcher/files/usr/sbin/nodewatcher b/src/packages/fff/fff-nodewatcher/files/usr/sbin/nodewatcher
> index 3733ef2..b9fb890 100755
> --- a/src/packages/fff/fff-nodewatcher/files/usr/sbin/nodewatcher
> +++ b/src/packages/fff/fff-nodewatcher/files/usr/sbin/nodewatcher
> @@ -9,20 +9,20 @@ test -f /tmp/started || exit
>  #Get the configuration from the uci configuration file
>  #If it does not exists, then get it from a normal bash file with variables.
>  if [ -f /etc/config/nodewatcher ];then
> -    SCRIPT_ERROR_LEVEL=`uci get nodewatcher.@script[0].error_level`
> -    SCRIPT_LOGFILE=`uci get nodewatcher.@script[0].logfile`
> -    SCRIPT_DATA_FILE=`uci get nodewatcher.@script[0].data_file`
> -    MESH_INTERFACE=`uci get nodewatcher.@network[0].mesh_interface`
> -    IFACEBLACKLIST=`uci get nodewatcher.@network[0].iface_blacklist`
> -    IPWHITELIST=`uci get nodewatcher.@network[0].ip_whitelist`
> -    SCRIPT_STATUS_FILE=`uci get nodewatcher.@script[0].status_text_file`
> +    SCRIPT_ERROR_LEVEL=$(uci get nodewatcher.@script[0].error_level)
> +    SCRIPT_LOGFILE=$(uci get nodewatcher.@script[0].logfile)
> +    SCRIPT_DATA_FILE=$(uci get nodewatcher.@script[0].data_file)
> +    MESH_INTERFACE=$(uci get nodewatcher.@network[0].mesh_interface)
> +    IFACEBLACKLIST=$(uci get nodewatcher.@network[0].iface_blacklist)
> +    IPWHITELIST=$(uci get nodewatcher.@network[0].ip_whitelist)
> +    SCRIPT_STATUS_FILE=$(uci get nodewatcher.@script[0].status_text_file)
>  else
> -    . `dirname $0`/nodewatcher_config
> +    . "$(dirname "$0")/nodewatcher_config"
>  fi
>  
> -if [ $SCRIPT_ERROR_LEVEL -gt "1" ]; then
> +if [ "$SCRIPT_ERROR_LEVEL" -gt "1" ]; then
>      err() {
> -        echo $1 >> $SCRIPT_LOGFILE
> +        echo "$1" >> "$SCRIPT_LOGFILE"
>      }
>  else
>      err() {
> @@ -32,10 +32,10 @@ fi
>  
>  #this method checks id the logfile has bekome too big and deletes the first X lines
>  delete_log() {
> -    if [ -f $SCRIPT_LOGFILE ]; then
> -        if [ `ls -la $SCRIPT_LOGFILE | awk '{ print $5 }'` -gt "6000" ]; then
> -            sed -i '1,60d' $SCRIPT_LOGFILE
> -            err "`date`: Logfile has been made smaller"
> +    if [ -f "$SCRIPT_LOGFILE" ]; then
> +        if [ "$(find "$SCRIPT_LOGFILE" -printf "%s")" -gt "6000" ]; then
> +            sed -i '1,60d' "$SCRIPT_LOGFILE"
> +            err "$(date): Logfile has been made smaller"
>          fi
>      fi
>  }
> @@ -54,7 +54,7 @@ inArray() {
>  #and provided by a small local httpd
>  crawl() {
>      #Get system data from other locations
> -    err "`date`: Collecting basic system status data"
> +    err "$(date): Collecting basic system status data"
>      hostname="$(cat /proc/sys/kernel/hostname)"
>      description="$(uci get system.@system[0].description)"
>      if [ -n "$description" ]; then
> @@ -87,10 +87,10 @@ crawl() {
>          /platform/ { printf "<chipset>"$2"</chipset>" }
>      ' /proc/cpuinfo)
>      model="<model>$(cat /var/sysinfo/model)</model>"
> -    local_time="`date +%s`"
> +    local_time="$(date +%s)"
>      load=$(awk '{ printf "<loadavg>"$3"</loadavg><processes>"$4"</processes>" }' /proc/loadavg)
>  
> -    err "`date`: Collecting version information"
> +    err "$(date): Collecting version information"
>  
>      batman_adv_version=$(cat /sys/module/batman_adv/version)
>      kernel_version=$(uname -r)
> @@ -146,12 +146,13 @@ crawl() {
>      SYSTEM_DATA=$SYSTEM_DATA"<openwrt_core_revision>$OPENWRT_CORE_REVISION</openwrt_core_revision>"
>      SYSTEM_DATA=$SYSTEM_DATA"<openwrt_feeds_packages_revision>$OPENWRT_FEEDS_PACKAGES_REVISION</openwrt_feeds_packages_revision>"
>  
> -    err "`date`: Collecting information from network interfaces"
> +    err "$(date): Collecting information from network interfaces"
>  
>      #Get interfaces
>      interface_data=""	
>      #Loop interfaces
> -    for filename in `grep 'up\|unknown' /sys/class/net/*/operstate`; do
> +    #for entry in $IFACES; do
> +    for filename in $(grep 'up\|unknown' /sys/class/net/*/operstate); do
>          ifpath=${filename%/operstate*}
>          iface=${ifpath#/sys/class/net/}
>          if inArray "$IFACEBLACKLIST" "$iface"; then
> @@ -159,23 +160,25 @@ crawl() {
>          fi
>  
>          #Get interface data for whitelisted interfaces
> +        # shellcheck disable=SC2016
>          awkscript='
>              /ether/ { printf "<mac_addr>"$2"</mac_addr>" }
>              /mtu/ { printf "<mtu>"$5"</mtu>" }'
>          if inArray "$IPWHITELIST" "$iface"; then
> +            # shellcheck disable=SC2016
>              awkscript=$awkscript'
>                  /inet / { split($2, a, "/"); printf "<ipv4_addr>"a[1]"</ipv4_addr>" }
>                  /inet6/ && /scope global/ { printf "<ipv6_addr>"$2"</ipv6_addr>" }
>                  /inet6/ && /scope link/ { printf "<ipv6_link_local_addr>"$2"</ipv6_link_local_addr>"}'
>          fi
> -        addrs=$(ip addr show dev ${iface} | awk "$awkscript")
> +        addrs=$(ip addr show dev "${iface}" | awk "$awkscript")
>  
> -        traffic_rx=`cat $ifpath/statistics/rx_bytes`
> -        traffic_tx=`cat $ifpath/statistics/tx_bytes`
> +        traffic_rx=$(cat "$ifpath/statistics/rx_bytes")
> +        traffic_tx=$(cat "$ifpath/statistics/tx_bytes")
>  
>          interface_data=$interface_data"<$iface><name>$iface</name>$addrs<traffic_rx>$traffic_rx</traffic_rx><traffic_tx>$traffic_tx</traffic_tx>"
>  
> -        interface_data=$interface_data$(iwconfig ${iface} 2>/dev/null | awk -F':' '
> +        interface_data=$interface_data$(iwconfig "${iface}" 2>/dev/null | awk -F':' '
>              /Mode/{ split($2, m, " "); printf "<wlan_mode>"m[1]"</wlan_mode>" }
>              /Cell/{ split($0, c, " "); printf "<wlan_bssid>"c[5]"</wlan_bssid>" }
>              /ESSID/ { split($0, e, "\""); printf "<wlan_essid>"e[2]"</wlan_essid>" }
> @@ -184,7 +187,7 @@ crawl() {
>          ')"</$iface>"
>      done
>  
> -    err "`date`: Collecting information from batman advanced and it´s interfaces"
> +    err "$(date): Collecting information from batman advanced and it´s interfaces"
>      #B.A.T.M.A.N. advanced
>      if [ -f /sys/module/batman_adv/version ]; then
>          for iface in $(grep active /sys/class/net/*/batman_adv/iface_status); do
> @@ -229,16 +232,16 @@ crawl() {
>                  i++
>              }' /sys/kernel/debug/batman_adv/bat0/gateways)
>      fi
> -    err "`date`: Collecting information about conected clients"
> +    err "$(date): Collecting information about conected clients"
>      #CLIENTS
>      client_count=0
>      CLIENT_INTERFACES=$(bridge link | awk '$2 !~/^bat/{ printf $2" " }')
>      for clientif in ${CLIENT_INTERFACES}; do
> -        local cc=$(bridge fdb show br $MESH_INTERFACE brport $clientif | grep -v self | grep -v permanent -c)
> -        client_count=$((client_count + $cc))
> +        local cc=$(bridge fdb show br "$MESH_INTERFACE" brport "$clientif" | grep -v self | grep -v permanent -c)
> +        client_count=$((client_count + cc))
>      done
>  
> -    err "`date`: Putting all information into a XML-File and save it at "$SCRIPT_DATA_FILE
> +    err "$(date): Putting all information into a XML-File and save it at $SCRIPT_DATA_FILE"
>  
>      DATA="<?xml version='1.0' standalone='yes'?><data>"
>      DATA=$DATA"<system_data>$SYSTEM_DATA</system_data>"
> @@ -251,19 +254,19 @@ crawl() {
>      DATA=$DATA"</data>"
>  
>      #write data to hxml file that provides the data on httpd
> -    SCRIPT_DATA_DIR=$(dirname $SCRIPT_DATA_FILE)
> -    test -d $SCRIPT_DATA_DIR || mkdir -p $SCRIPT_DATA_DIR
> -    echo $DATA | gzip | tee $SCRIPT_DATA_FILE | alfred -s 64
> +    SCRIPT_DATA_DIR=$(dirname "$SCRIPT_DATA_FILE")
> +    test -d "$SCRIPT_DATA_DIR" || mkdir -p "$SCRIPT_DATA_DIR"
> +    echo "$DATA" | gzip | tee "$SCRIPT_DATA_FILE" | alfred -s 64
>  }
>  
>  LANG=C
>  
>  #Prüft ob das logfile zu groß geworden ist
> -err "`date`: Check logfile"
> +err "$(date): Check logfile"
>  delete_log
>  
>  #Erzeugt die statusdaten
> -err "`date`: Generate actual status data"
> +err "$(date): Generate actual status data"
>  crawl
>  
>  exit 0
> -- 
> 2.1.4
>