Problem while doing a cat on a tabbed file with pexpect

Steven D'Aprano steve+comp.lang.python at
Sun Jan 15 21:01:35 EST 2012

On Sun, 15 Jan 2012 09:51:44 -0800, Saqib Ali wrote:

> I am using Solaris 10, python 2.6.2, pexpect 2.4

Are you sure about that? As far as I can see, pexpect's current version 
is 2.3 not 2.4.

> I create a file called me.txt which contains the letters "A", "B", "C"
> on the same line separated by tabs.
> My shell prompt is "% "
> I then do the following in the python shell:
>>>> import pexpect
>>>> x = pexpect.spawn("/bin/tcsh")

Can you try another shell, just in case tcsh is converting the tabs to 

>>>> x.sendline("cat me.txt")
> 11

What happens if you do this from the shell directly, without pexpect? It 
is unlikely, but perhaps the problem lies with cat rather than pexpect. 
You should eliminate this possibility.

>>>> x.expect([pexpect.TIMEOUT, "% "])
> 1
>>>> x.before
> 'cat me.txt\r\r\nA       B       C\r\n'

Unfortunately I can't replicate the same behaviour, however my setup is 
different. I'm using pexpect2.3 on Linux, and I tried it using bash and 
sh but not tcsh. In all my tests, the tabs were returned as expected.

(However, the x.expect call returned 0 instead of 1, even with the shell 
prompt set correctly.)


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