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Re: Mimick tac with python.

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Subject Re: Mimick tac with python.
Date Fri, 29 Jan 2016 23:58:38 -0500
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On Fri, Jan 29, 2016, at 23:46, Hongyi Zhao wrote:
> Hi all,
> 
> I can use the following methods for mimicking tac command bellow:
> 
> awk '{a[NR]=$0} END {while (NR) print a[NR--]}' input_file
> perl -e 'print reverse<>' input_file

Well, both of those read the whole file into memory - tac is sometimes
smarter than that, but that makes for a more complex program. And python
doesn't really do "one-liners" like that, so it doesn't look quite as
nice. But combined with some shell constructs you can do:

python <(echo 'import sys;print("".join(reversed(list(sys.stdin))))')

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Thread

Mimick tac with python. Hongyi Zhao <hongyi.zhao@gmail.com> - 2016-01-30 04:46 +0000
  Re: Mimick tac with python. Random832 <random832@fastmail.com> - 2016-01-29 23:58 -0500
    Re: Mimick tac with python. Christian Gollwitzer <auriocus@gmx.de> - 2016-01-30 07:03 +0100
      Re: Mimick tac with python. Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-01-30 09:56 +0200
        Re: Mimick tac with python. Christian Gollwitzer <auriocus@gmx.de> - 2016-01-30 10:23 +0100
      Re: Mimick tac with python. Peter Otten <__peter__@web.de> - 2016-01-30 09:21 +0100
      Re: Mimick tac with python. Terry Reedy <tjreedy@udel.edu> - 2016-01-30 04:38 -0500
    Re: Mimick tac with python. Hongyi Zhao <hongyi.zhao@gmail.com> - 2016-01-30 06:18 +0000
  Re: Mimick tac with python. Chris Angelico <rosuav@gmail.com> - 2016-01-30 15:56 +1100

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