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devel / comp.unix.shell / Re: About the end of line symbols displayed by `cat -ve'.

Re: About the end of line symbols displayed by `cat -ve'.

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https://www.novabbs.com/devel/article-flat.php?id=4250&group=comp.unix.shell#4250

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From: lew.pitc...@digitalfreehold.ca (Lew Pitcher)
Newsgroups: comp.unix.shell
Subject: Re: About the end of line symbols displayed by `cat -ve'.
Date: Sat, 21 Aug 2021 15:49:54 -0000 (UTC)
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by: Lew Pitcher - Sat, 21 Aug 2021 15:49 UTC

On Sat, 21 Aug 2021 06:55:45 -0700, hongy...@gmail.com wrote:

> See the following testing:
>
> $ cat -ve aaa
> bla^M$
>
> Why don't the end of line symbols displayed as `^M^J'?

Because unix tools expect text lines to end with the ^J
LineFeed character, and the cat(1) -v option will
"use ^ and M- notation, EXCEPT for LFD (linefeed) and
TAB".
So, you don't get to see the ^J at the end of a unix text
line with the cat(1) -v option.

However, the cat(1) -E option (invoked when you specified
-e) will
"display $ at end of each line"
where the ^J unix text line terminator would appear.

As to why cat(1) gives you ^M$ instead of just $, it appears
that you fed cat(1) with an MSDOS/MSWindows plain text file,
and MSDOS/MSWindows terminates each text line with the ASCII
character pair of Carriage Return (^M) followed by LineFeed
(^J). cat(1) doesn't speak MSDOS/MSWindows, and knows nothing
of it's quirks.

HTH
--
Lew Pitcher
"In Skills, We Trust"

Subject	Author
Re: About the end of line symbols displayed by `cat -ve'.	Lew Pitcher