Inner loop won't break - bash

Question

code works but won't continue to run the loop stuck in the inner loop not sure where the problem is, or maybe port scan just takes alot of time
#!/bin/bash
up()
{
ping -c 1 $1 > /dev/null
[ $? -eq 0 ] && echo IP: $i is up.
}
for i in 192.168.0.{1..255}
do
up $i & disown
for port in {1..100};do
2>/dev/null echo > /dev/tcp/$i/$port
if [ $? == 0 ]
then
{
echo "port $port is open"
continue
}
fi
done
done
exit

Answer 1

Scan Ping + TCP in bash
I've tried to limit script to 8182 forks in order to stay polite.
This script scan /etc/services, then could scan all (desired) ports. (see comments).
Full scan of my complex private subnet take more than 5 minutes to complete (scanning 303 ports on 255 hosts, found 27 up)!
#!/bin/bash
BaseIP=${1:-192.168.1}
ports=(21 22 25 80 443 9100)
# ports=({1..100}) # Uncomment this for ports 1-100
while IFS=$' \t\r\n/' read serv port prot comm ;do
[ "$prot" = "tcp" ] && printf -v $prot[$port] %s "$serv"
done </etc/services
# ports=(${!tcp[#]}) # Uncomment this for all known ports
isup() { ping -W 1 -c1 -n $1 &>/dev/null && printf "IP: %-17sis up.\n" $1;}
tstport() { local _tst _prot=${3:-tcp}; local -n _var=$_prot[$2]
{
exec {_tst}<>/dev/$_prot/$1/$2 && exec {_tst}<&- &&
printf "IP: %-16s port %6d open (%s)\n" $1 $2 ${_var:-unassigned}
} 2>/dev/null
}
step=$((8180/(${#ports[#]}+1)))
for ((i=1;i < 255;i+=step)) {
max=$((i+step>255?255:i+step))
for ((l=i;l<max;l++)) {
isup $BaseIP.$l &
exec {dummy}< <(:)
for port in ${ports[#]} ;do
exec {dummy2}< <(:)
tstport $BaseIP.$l $port & read -u $dummy2 -t .02
exec {dummy2}<&-
done &
read -u $dummy -t .02
exec {dummy}<&-
} |
sed -une /./p
}
Sorted ouptut could look like:
IP: 192.168.1.1 is up.
IP: 192.168.1.3 is up.
IP: 192.168.1.3 port 22 open (ssh)
IP: 192.168.1.15 is up.
IP: 192.168.1.15 port 22 open (ssh)
IP: 192.168.1.15 port 139 open (netbios-ssn)
IP: 192.168.1.15 port 445 open (microsoft-ds)
IP: 192.168.1.15 port 515 open (printer)
IP: 192.168.1.39 is up.
IP: 192.168.1.39 port 22 open (ssh)