Restrict or limit read_very_eager() in python

Question

I am executing a few commands on a remote machine which runs linux over a telnet session using telnet lib. When I give the following :

tn.write("<binary_name>")
time.sleep(10)
tn.write("cat <path_of_output_file>")
rd_buf=tn.read_very_eager()
print(rd_buf)

it gives the output of the binary and the output of cat command. While I only want the output of the cat command. I have only worked with read_very_eager and read_until. How do I restrict my buffer variable to hold only the contents of the cat command?

Answer 1

After a bit of playing around with read_until() and read_very_eager(), I finally solved this. All I had to do was this :

tn.write("<binary_name>")
time.sleep(10)
junk=tn.read_very_eager()
tn.write("cat <path_of_output_file>")
rd_buf=tn.read_very_eager()
print(rd_buf)

With the addition of 1 line (junk=tn.read_very_eager()), I am able to achieve what I wanted. Quoting the python official documentation :

Telnet.read_very_eager()

Read everything that can be without blocking in I/O (eager).

I took a cue from this and made the script forcefully halt the "reading". And begin reading all over again, which served the purpose.