Re: [PATCH] git-prompt: fix reading files with windows line endings

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Nov 30, 2017, 00:21 UTC
Message-ID: <alpine.DEB.2.21.1.1711300100320.6482@virtualbox>
In-Reply-To: <d57e4cb9-b0b4-314e-370a-e0db58a2a7da@robertabel.eu>

Hi Robert,

On Wed, 29 Nov 2017, Robert Abel wrote:

Show 11 quoted lines

> On 29 Nov 2017 15:27, Johannes Schindelin wrote:
>
> > Or maybe keep with the Bash construct, but guarded behind a test that we
> > area actually running in Bash? Something like
> > 
> > 	test -z "$BASH" || IFS=$' \t\r\n'
> 
> Actually, this got me thinking and reading the POSIX.1-2008, specifically
> http://pubs.opengroup.org/onlinepubs/9699919799/utilities/read.html.
> 
> It seems POSIX states that IFS should be supported by read.

Yes, that's what I meant: you could use IFS.

> This means that it should be okay to just do
> 
> > test -r "$f" && IFS=" \t\r\n" read "$@" < "$f"

I am afraid that this won't work: when I call

	printf '123\r\n' |
	while IFS=" \t\r\n" read line
	do
		printf '%s' "$line" |
		hexdump -C
	done

it prints

	00000000  31 32 33 0d                               |123.|
	00000004

If I replace the double-quoted IFS by the dollar-single-quoted one, it works again. I think the reason is that \t, \r and \n are used literally when double-quoted, not as <HT>, <CR> and <LF>.

Ciao, Johannes