minor fixes to sh scripts to be POSIX compliant

Author: FrancYescO

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 ] || [ ! "$(< /etc/crontabs/root grep checkver)" ]; then
+		if [ ! -f /etc/crontabs/root ] || [ ! grep -q "checkver" /etc/crontabs/root ]; then
 			rand_h=$(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 ] || [ "$(< /etc/crontabs/root grep -c "christmas_tree")" -lt 1 ]; 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

@@ -346,7 +346,7 @@ mobiled_lib_add() {
     /etc/init.d/mobiled restart
   else
     #make sure we haven't replaced it some old GUI install, restore from rom if needed
-    if [[ -f /rom/etc/init.d/mobiled && -n "$(cmp /rom/etc/init.d/mobiled /etc/init.d/mobiled)" ]]; then
+    if [ -f /rom/etc/init.d/mobiled ] && [ -n "$(cmp /rom/etc/init.d/mobiled /etc/init.d/mobiled)" ]; then
       logecho "Restoring and restarting /etc/init.d/mobiled ..."
       cp /rom/etc/init.d/mobiled /etc/init.d/mobiled
       /etc/init.d/mobiled restart

decompressed/gui_file/etc/modgui_scripts/05_app.sh

@@ -36,7 +36,7 @@ trafficmon_support() {
 		rm -rf /root/trafficmon
 	fi
 
-	if [ -n "$(< /etc/crontabs/root grep trafficmon)" ]; then
+	if grep -q trafficmon /etc/crontabs/root; then
 		killall trafficmon 2>/dev/null
 		killall trafficdata 2>/dev/null
 		sed -i '/trafficmon/d' /etc/crontabs/root

decompressed/gui_file/etc/modgui_scripts/99_postreq.sh

@@ -29,7 +29,7 @@ start_stop_nginx() {
 	done
 
 	nginx_count=0
-	while [ "$(curl 127.0.0.1 --max-time 20 -I -s | head -n 1 | cut -d$' ' -f2)" != "200" ] && [ $nginx_count -lt 5 ]; do
+	while [ "$(curl 127.0.0.1 --max-time 20 -I -s | head -n 1 | cut -d' ' -f2)" != "200" ] && [ $nginx_count -lt 5 ]; do
 		if [ $nginx_count -gt 3 ]; then
 			if [ -f /var/run/nginx.pid ]; then
 				kill -KILL "$(cat /var/run/nginx.pid)"