Telnet BASH script - output not saved

Question

I'm running a very simple telnet bash script and it works.

#!/bin/sh
host=90.205.177.129
port=23
login=admin
passwd=Sky.2015
#cmd1=sh
cmd2=meminfo > /tmp/top.txt

echo open ${host} ${port}
sleep 5
echo ${login}
sleep 5
echo ${passwd}
sleep 10
#echo ${cmd1}
#sleep 5
echo ${cmd2}
sleep 20
echo exit

However, the output of meminfo is not copied on "top.txt" file. The file is created

root@raspberrypi:/etc/my_scripts# ls -l /tmp/
total 12
-rw-r--r-- 1 root root 784 Oct 13 14:32 1wall_test1_S.txt
-rw-r--r-- 1 root root 216 Oct 14 11:28 test_l.txt
-rw-r--r-- 1 root root 216 Oct 14 11:37 test_s.txt
-rwxrwxrwx 1 root root   0 Oct 15 09:35 top.txt
root@raspberrypi:/etc/my_scripts#

Any suggestion?

Answer 1

the problem lies in

cmd2=meminfo > /tmp/top.txt

this actualy sets the variable cmd2 to meminfo and evaluates the redirection. you should quote this.

cmd2='meminfo > /tmp/top.txt'

edit: this creates the file on the target. according to your own answer you wanted to create it on the system that runs the script (not stated in your original question). the cause is still valid, but the solution is not.

Answer 2

Use alias cmd2="meminfo > /tmp/top.txt" to create an alias command, instead of using an environment variable called cmd2.

Answer 3

Found the solution by myself :)

./telnet.sh | telnet > /tmp/top.txt 

In this way I redirect the command to an output file. However, I have to run the same script many times and I don't want overwrite the same file, but I would create and incremental file (good idea would be renamed with DATE command).

to use a date option

./telnet.sh | telnet > /tmp/top-$(date +%Y%m%d-%T).txt