minor fixes to sh scripts to be POSIX compliant

Author: FrancYescO

decompressed/gui_file/etc/modgui_scripts/02_specific.sh

@@ -18,7 +18,7 @@ extract_with_check() {
       continue
     fi
 
-    [ -n "$(echo "$file" | grep .md5sum)" ] && continue
+    grep -q '.md5sum' "$file" && continue
 
     orig_file=/$file
     file=$MD5_CHECK_DIR/$file

decompressed/gui_file/etc/modgui_scripts/03_various.sh

@@ -121,7 +121,7 @@ checkver_cron() {
 				rm /etc/crontabs/root #THIS CHECK A VALID ROOT CRON... we remove it as it's useless if the owner is not root.
 			fi
 		fi
-		if [ ! -f /etc/crontabs/root ] || [ ! grep -q "checkver" /etc/crontabs/root ]; then
+		if [ ! -f /etc/crontabs/root ] || ! grep -q "checkver" /etc/crontabs/root; then
 			rand_h=$(awk -v min=1 -v max=6 'BEGIN{srand(); print int(min+rand()*(max-min+1))}')
 			rand_m=$(awk -v min=1 -v max=59 'BEGIN{srand(); print int(min+rand()*(max-min+1))}')
 			echo "$rand_m $rand_h * * * /usr/share/transformer/scripts/checkver >/dev/null 2>&1" >> /etc/crontabs/root
@@ -131,7 +131,7 @@ checkver_cron() {
 }
 
 cron_christmas() {
-	if [ ! -f /etc/crontabs/root ] || [ ! grep -q "christmas_tree" /etc/crontabs/root ]; then
+	if [ ! -f /etc/crontabs/root ] || ! grep -q "christmas_tree" /etc/crontabs/root; then
 		echo "*/30 * 24-26 12 * /etc/christmas_tree.sh &" >> /etc/crontabs/root
 	fi
 }

decompressed/gui_file/etc/modgui_scripts/04_config.sh

@@ -112,7 +112,7 @@ eco_param() {
     uci set power.cpu.cpuspeed='256'
     uci set power.cpu.wait='1'
     logecho "Restarting power management"
-    /etc/init.d/power restart &>/dev/null
+    /etc/init.d/power restart >/dev/null 2>&1
   fi
 }
 
@@ -498,11 +498,11 @@ cumulative_check_gui() {
 
   if [ ! "$(uci get -q modgui.gui.gui_hash)" ]; then
     uci set modgui.gui.new_ver="Unknown"
-    uci set modgui.gui.gui_hash=$gui_hash
+    uci set modgui.gui.gui_hash="$gui_hash"
     uci set modgui.gui.outdated_ver='0'
-  elif [ "$(uci get -q modgui.gui.gui_hash)" != $gui_hash ]; then
+  elif [ "$(uci get -q modgui.gui.gui_hash)" != "$gui_hash" ]; then
     uci set modgui.gui.new_ver="Unknown"
-    uci set modgui.gui.gui_hash=$gui_hash
+    uci set modgui.gui.gui_hash="$gui_hash"
     uci set modgui.gui.outdated_ver='0'
   fi
   if [ ! "$(uci get -q modgui.gui.autoupgrade)" ]; then

decompressed/gui_file/etc/modgui_scripts/06_network.sh

@@ -102,7 +102,7 @@ puryfy_wan_interface() { #creano problemi di dns per chissa'  quale diavolo di
 fix_dns_dhcp_bug() {
   logecho "Fix DNS bug, make sure odhcp is enabled"
   #SET odhcpd MAINDHCP to 0 to use dnsmasq for ipv4
-  if [ "$(uci get -q dhcp.odhcpd.maindhcp)" == "1" ]; then
+  if [ "$(uci get -q dhcp.odhcpd.maindhcp)" = "1" ]; then
     logecho "Setting odhcpd not maindhcp"
     uci set dhcp.odhcpd.maindhcp="0"
     /etc/init.d/odhcpd restart
@@ -214,10 +214,10 @@ unlock_ssh_wan_tiscali() {
 
 disable_tcp_Sack() {
   logecho "Apply CVE 2019-11477 workaround"
-  if [ "$(cat /etc/sysctl.conf | grep 'net.ipv4.tcp_sack')" ]; then
+  if grep -q 'net.ipv4.tcp_sack' /etc/sysctl.conf; then
     sed -i 's/\(net.ipv4.tcp_sack=\)1/\10/g' /etc/sysctl.conf
     sysctl -p 2>/dev/null 1>/dev/null
-  elif [ -n "$(cat /etc/sysctl.conf | grep 'net.ipv4.tcp_sack=0')" ]; then
+  elif ! grep -q 'net.ipv4.tcp_sack=0' /etc/sysctl.conf; then
     echo -e "\n" >>/etc/sysctl.conf
     echo "# disable tcp_sack for CVE 2019-11477" >>/etc/sysctl.conf
     echo "net.ipv4.tcp_sack=0" >>/etc/sysctl.conf
@@ -260,7 +260,7 @@ disable_tcp_Sack
 check_xtm_atmwan #needed for UNO firmware
 
 logecho "Restarting dnsmasq if needed..."
-if [ $restart_dnsmasq -eq 1 ]; then
+if [ "$restart_dnsmasq" -eq 1 ]; then
   uci commit
   killall dnsmasq
   /etc/init.d/dnsmasq restart