Telnet connection stops bash script












0














I have a bash script where I continuously read from a text file the hosts and port and create a connection to check for the status.



My code is:



while IFS=";" read -r host ports
do
eval "arr=($ports)"
for port in "${arr[@]}";
do
echo "connecting to $host on port $port" >> output.txt
timeout 5s telnet $host $port
exit_status=$?
if [[ $exit_status -eq 124 ]]; then
echo "$host on $port has timed out" >> output.txt
else
telnet $host $port >> output.txt
fi
echo "---------------------------------------------" >> output.txt
done
done < "$1"


The first if is to check if the connection timeouts.
That works as expected.



In the else block the script exits if the connection has been established. I am not sure why this happens.



It stops by spitting out:



Escape character is '^]'.
Connection closed by foreign host.


I am looking for it to write to the output file status of the connection.










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  • What do you mean, "file status"? You've determined that the port didn't time out, but what's the point of the telnet connection? Are you hoping to establish a connection and execute a command?
    – Jeff Schaller
    56 mins ago
















0














I have a bash script where I continuously read from a text file the hosts and port and create a connection to check for the status.



My code is:



while IFS=";" read -r host ports
do
eval "arr=($ports)"
for port in "${arr[@]}";
do
echo "connecting to $host on port $port" >> output.txt
timeout 5s telnet $host $port
exit_status=$?
if [[ $exit_status -eq 124 ]]; then
echo "$host on $port has timed out" >> output.txt
else
telnet $host $port >> output.txt
fi
echo "---------------------------------------------" >> output.txt
done
done < "$1"


The first if is to check if the connection timeouts.
That works as expected.



In the else block the script exits if the connection has been established. I am not sure why this happens.



It stops by spitting out:



Escape character is '^]'.
Connection closed by foreign host.


I am looking for it to write to the output file status of the connection.










share|improve this question







New contributor




Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




















  • What do you mean, "file status"? You've determined that the port didn't time out, but what's the point of the telnet connection? Are you hoping to establish a connection and execute a command?
    – Jeff Schaller
    56 mins ago














0












0








0







I have a bash script where I continuously read from a text file the hosts and port and create a connection to check for the status.



My code is:



while IFS=";" read -r host ports
do
eval "arr=($ports)"
for port in "${arr[@]}";
do
echo "connecting to $host on port $port" >> output.txt
timeout 5s telnet $host $port
exit_status=$?
if [[ $exit_status -eq 124 ]]; then
echo "$host on $port has timed out" >> output.txt
else
telnet $host $port >> output.txt
fi
echo "---------------------------------------------" >> output.txt
done
done < "$1"


The first if is to check if the connection timeouts.
That works as expected.



In the else block the script exits if the connection has been established. I am not sure why this happens.



It stops by spitting out:



Escape character is '^]'.
Connection closed by foreign host.


I am looking for it to write to the output file status of the connection.










share|improve this question







New contributor




Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











I have a bash script where I continuously read from a text file the hosts and port and create a connection to check for the status.



My code is:



while IFS=";" read -r host ports
do
eval "arr=($ports)"
for port in "${arr[@]}";
do
echo "connecting to $host on port $port" >> output.txt
timeout 5s telnet $host $port
exit_status=$?
if [[ $exit_status -eq 124 ]]; then
echo "$host on $port has timed out" >> output.txt
else
telnet $host $port >> output.txt
fi
echo "---------------------------------------------" >> output.txt
done
done < "$1"


The first if is to check if the connection timeouts.
That works as expected.



In the else block the script exits if the connection has been established. I am not sure why this happens.



It stops by spitting out:



Escape character is '^]'.
Connection closed by foreign host.


I am looking for it to write to the output file status of the connection.







bash shell-script telnet






share|improve this question







New contributor




Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question







New contributor




Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question






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Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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asked 1 hour ago









Ronakh Thaikkat

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New contributor




Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor





Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Ronakh Thaikkat is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












  • What do you mean, "file status"? You've determined that the port didn't time out, but what's the point of the telnet connection? Are you hoping to establish a connection and execute a command?
    – Jeff Schaller
    56 mins ago


















  • What do you mean, "file status"? You've determined that the port didn't time out, but what's the point of the telnet connection? Are you hoping to establish a connection and execute a command?
    – Jeff Schaller
    56 mins ago
















What do you mean, "file status"? You've determined that the port didn't time out, but what's the point of the telnet connection? Are you hoping to establish a connection and execute a command?
– Jeff Schaller
56 mins ago




What do you mean, "file status"? You've determined that the port didn't time out, but what's the point of the telnet connection? Are you hoping to establish a connection and execute a command?
– Jeff Schaller
56 mins ago










1 Answer
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Both telnet commands will attempt to read from the remains of your $1 file, whatever that may be. So your loop may get executed an unexpectedly fewer number of times.



I'm not sure what input you were expecting to provide to telnet though.



Incidentally, if you have it installed you'd be better off using netcat (sometimes known as nc). It won't solve it change the input issue but it is usually a better tool for this kind of scripted interaction.






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    Both telnet commands will attempt to read from the remains of your $1 file, whatever that may be. So your loop may get executed an unexpectedly fewer number of times.



    I'm not sure what input you were expecting to provide to telnet though.



    Incidentally, if you have it installed you'd be better off using netcat (sometimes known as nc). It won't solve it change the input issue but it is usually a better tool for this kind of scripted interaction.






    share|improve this answer




























      1














      Both telnet commands will attempt to read from the remains of your $1 file, whatever that may be. So your loop may get executed an unexpectedly fewer number of times.



      I'm not sure what input you were expecting to provide to telnet though.



      Incidentally, if you have it installed you'd be better off using netcat (sometimes known as nc). It won't solve it change the input issue but it is usually a better tool for this kind of scripted interaction.






      share|improve this answer


























        1












        1








        1






        Both telnet commands will attempt to read from the remains of your $1 file, whatever that may be. So your loop may get executed an unexpectedly fewer number of times.



        I'm not sure what input you were expecting to provide to telnet though.



        Incidentally, if you have it installed you'd be better off using netcat (sometimes known as nc). It won't solve it change the input issue but it is usually a better tool for this kind of scripted interaction.






        share|improve this answer














        Both telnet commands will attempt to read from the remains of your $1 file, whatever that may be. So your loop may get executed an unexpectedly fewer number of times.



        I'm not sure what input you were expecting to provide to telnet though.



        Incidentally, if you have it installed you'd be better off using netcat (sometimes known as nc). It won't solve it change the input issue but it is usually a better tool for this kind of scripted interaction.







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited 32 mins ago

























        answered 57 mins ago









        roaima

        42.8k551116




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