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Re: Problem while doing a cat on a tabbed file with pexpect

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On 15Jan2012 16:14, Saqib Ali <saqib.ali.75@gmail.com> wrote:
| The file me.txt does indeed contain tabs. I created it with vi.
| 
| >>> text = open("me.txt", "r").read()
| >>> print "\t" in text
| True
| 
| % od -c me.txt
| 0000000   A  \t   B  \t   C  \n
| 0000006
| 
| % ls -al me.txt
| -rw-r--r--   1 myUser    myGroup   6 Jan 15 12:42 me.txt

Ok, your file does indeed contain TABs.

Therefre something is turning the TABs into spaces. Pexpect should be
opening a pty and reading from that, and I do not expect that to expand
TABs. So:

  1: Using subprocess.Popen, invoke "cat me.txt" and check the result
     for TABs.

  2: Using pexpect, run "cat me.txt" instead of "/bin/tcsh" (eliminates a
     layer of complexity; I don't actually expect changed behaviour) and
     check for TABs.

On your Solaris system, read "man termios". Does it have an "expand
TABs" mode switch? This is about the only thing I can think of that
would produce your result - the pty terminal discipline is expanding
TABs for your (unwanted!) - cat is writing TABs to the terminal and the
terminal is passing expanded spaces to pexpect. Certainly terminal line
disciplines do rewrite stuff, most obviously "\n" into "\r\n", but a
quick glance through termios on a Linux box does not show a tab
expansion mode; I do not have access to a Solaris box at present.

Cheers,
-- 
Cameron Simpson <cs@zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/

Maintainer's Motto: If we can't fix it, it ain't broke.

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Problem while doing a cat on a tabbed file with pexpect Saqib Ali <saqib.ali.75@gmail.com> - 2012-01-15 09:51 -0800
  Re: Problem while doing a cat on a tabbed file with pexpect Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-01-15 14:24 -0500
    Re: Problem while doing a cat on a tabbed file with pexpect Saqib Ali <saqib.ali.75@gmail.com> - 2012-01-15 16:11 -0800
      Re: Problem while doing a cat on a tabbed file with pexpect Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-01-15 22:35 -0500
      Re: Problem while doing a cat on a tabbed file with pexpect Michael Torrie <torriem@gmail.com> - 2012-01-15 20:47 -0700
  Re: Problem while doing a cat on a tabbed file with pexpect Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-01-15 23:04 +0000
    Re: Problem while doing a cat on a tabbed file with pexpect Cameron Simpson <cs@zip.com.au> - 2012-01-16 10:40 +1100
      Re: Problem while doing a cat on a tabbed file with pexpect Saqib Ali <saqib.ali.75@gmail.com> - 2012-01-15 16:14 -0800
        Re: Problem while doing a cat on a tabbed file with pexpect Cameron Simpson <cs@zip.com.au> - 2012-01-16 12:45 +1100
  Re: Problem while doing a cat on a tabbed file with pexpect Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-01-16 02:01 +0000

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