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Re: What code make both `cat < /tmp/1.txt` and `< /tmp/1.txt cat` valid?
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From: |
Alex fxmbsw7 Ratchev |
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Subject: |
Re: What code make both `cat < /tmp/1.txt` and `< /tmp/1.txt cat` valid? |
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Date: |
Wed, 12 May 2021 13:25:37 +0200 |
there are different layers of affective command parts
> and < redirs are *coded* to be available everywhere nearly on the cmdline
so
.. ?
On Mon, May 10, 2021, 17:32 Peng Yu <pengyu.ut@gmail.com> wrote:
> I am trying to understand how bash is implemented
>
> $ seq 3 > /tmp/1.txt
> $ cat < /tmp/1.txt
> 1
> 2
> 3
> $ < /tmp/1.txt cat
> 1
> 2
> 3
>
> https://git.savannah.gnu.org/cgit/bash.git/tree/parse.y#n729
>
> I see `redirection_list` is just a list of redirection.
>
> redirection_list: redirection
> | redirection_list redirection
>
> But then it should be following `shell_command`. How come
> redirection_list can be anywhere in a command including the beginning?
>
> command:
> ...
> | shell_command redirection_list
>
> --
> Regards,
> Peng
>
>