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From: Ilkka Virta <itvirta@iki.fi>
Newsgroups: gnu.bash.bug
Subject: Re: Feature Request: Custom delimeter for single quotes
Date: Fri, 1 Nov 2019 10:37:50 +0200
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To: Patrick Blesi <patrick@ble.si>, bug-bash@gnu.org
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On 1.11. 06:54, Patrick Blesi wrote:
> I'm looking for a hybrid between single quotes and a here doc or here
> string.
>=20
> The main use case is for accepting arbitrary user-specified text.=20

Do your users enter the text by directly editing the script?
Would it make more sense to use e.g. 'read' to read the input directly=20
from the user?

input=3D""
nl=3D'
'
echo "Enter text, end with ^D:"
while IFS=3D read -r line; do
     input=3D"$input$line$nl"
done

printf "You entered:\n---\n%s---\n" "$input"


or to just have the text in a separate file (not the script) and read it=20
from there?

input=3D$(< inputfile)


That way, the text appears in a variable, and you don't need to care=20
about quotes inside it.


(You could also read from stdin with just  input=3D$(cat)  instead of the=
=20
while read loop but that feels a bit odd to me for some reason.)

> I would
> like to wrap this text in single quotes so as to prevent any variable
> expansion or interpretation of the text of any kind. Additionally, I wo=
uld
> like to allow the users to include single quotes in their text without
> requiring that they escape these quotes.
>=20
> Something akin to the following would alleviate the need to communicate
> that users must escape single quotes, but also provide the same literal
> string behavior of single quotes.
>=20
> presuming the arbitrarily substituted text is:
>=20
> echo 'this command is specified by the user'
>=20
> Then a syntax for this single quote heredoc behavior could be like:
>=20
> $ sh -c <<^MAGIC_WORD echo 'this command is specified by the user'
> MAGIC_WORD
>=20
> Everything within the MAGIC_WORD declarations would not have command
> substitution, variable expansion, etc, but would be treated as if it we=
re
> wrapped in single quotes with the exception that single quotes between =
the
> MAGIC_WORDs need not be escaped.
>=20
> Pardon my na=C3=AFvet=C3=A9, does any such feature exist or are there g=
ood ways to
> accomplish this? If not, is this something that could feasibly be
> implemented? Would it be desirable?
>=20
> Thanks,
>=20
> Patrick
>=20


--=20
Ilkka Virta / itvirta@iki.fi