Bug related to single-quoting a String

Bug related to single-quoting a String

[Ronald Fischer]

What I want to report can be a bugh either in the documentaion (man-page) or in the implementation, depending on which one is correct.

I am running Zsh 5.5.1 for Cygwin (which seems to be the most recent one available for this platform).

In the man-page, it says in the chapter about single-quoting a string:

    A literal ' character can be included in the string by using the \' escape.

Taken this at face value, the following should work:

    echo 'a$b\'c'

However, if I enter this in an interactive shell, Zsh reminds me that a closing single quote would be missing. The behaviour is as if \' can **not** be used to place a single quote inside a string surrounded by single quotes.

Incidentally, this behaviour is consistent with bash and dash, and the bash man-page says explicitly, that \' is not an escape inside a single-quoted string. Hence, the implementation of zsh mimics in this respect to what bash and POSIX shell are doing. 

I don't know, whether zsh was intended to behave in this way; if it is the case, the documentation is faulty. If the man page is considered right, the implementation is buggy.

(Crossposting note: I have discussed this issue at https://stackoverflow.com/questions/61095565/having-a-single-quote-inside-a-single-quoted-string?noredirect=1#comment108090871_61095565 - just in case you want to read the comments posted there, or also add something to that thread).

Ronald Fischer

Re: Bug related to single-quoting a String

[Roman Perepelitsa]

On Wed, Apr 8, 2020 at 12:40 PM Ronald Fischer <ynnor@mm.st> wrote:
>
> What I want to report can be a bugh either in the documentaion (man-page) or in the implementation, depending on which one is correct.
>
> I am running Zsh 5.5.1 for Cygwin (which seems to be the most recent one available for this platform).
>
> In the man-page, it says in the chapter about single-quoting a string:
>
>     A literal ' character can be included in the string by using the \' escape.

Here's the whole paragraph from which this quote is taken:

  A string enclosed between '$'' and ''' is processed the same way as the
  string arguments of the print builtin, and the resulting string is
  considered to be entirely quoted.  A literal ''' character can be
  included in the string by using the '\'' escape.

It's talking about $'...'. Both the documentation and the
implementation are correct.

Roman.

Re: Bug related to single-quoting a String

[Ronald Fischer]

On Wed, Apr 8, 2020, at 12:45, Roman Perepelitsa wrote:
> On Wed, Apr 8, 2020 at 12:40 PM Ronald Fischer <ynnor@mm.st> wrote:
> >
> > What I want to report can be a bugh either in the documentaion (man-page) or in the implementation, depending on which one is correct.
> >
> > I am running Zsh 5.5.1 for Cygwin (which seems to be the most recent one available for this platform).
> >
> > In the man-page, it says in the chapter about single-quoting a string:
> >
> >     A literal ' character can be included in the string by using the \' escape.
> 
> Here's the whole paragraph from which this quote is taken:
> 
>   A string enclosed between '$'' and ''' is processed the same way as the
>   string arguments of the print builtin, and the resulting string is
>   considered to be entirely quoted.  A literal ''' character can be
>   included in the string by using the '\'' escape.
> 
> It's talking about $'...'. Both the documentation and the
> implementation are correct.

However, if I do a

    echo $'a$b\'c'

it does not work either. Same effect!

Ronald

Re: Bug related to single-quoting a String

[Peter Stephenson]

> On 08 April 2020 at 11:39 Ronald Fischer <ynnor@mm.st> wrote:
> What I want to report can be a bugh either in the documentaion
> (man-page) or in the implementation, depending on which one is correct.
> 
> I am running Zsh 5.5.1 for Cygwin (which seems to be the most recent one available for this platform).
> 
> In the man-page, it says in the chapter about single-quoting a string:
> 
>     A literal ' character can be included in the string by using the \' escape.
> 
> Taken this at face value, the following should work:
> 
>     echo 'a$b\'c'

I believe you're looking at the documentation for the $'...' style of quoting.  So you can do

echo $'a$b\'c'

This style allows a bit more interpolation than ordinary single quotes.

pws

Re: Bug related to single-quoting a String

[Ronald Fischer]

> echo $'a$b\'c'
> 
> This style allows a bit more interpolation than ordinary single quotes.

My mistake: When I tried this first, it did not work, but I see that I had a typing error. I can get it working now.

Ronald

Re: Bug related to single-quoting a String

[Roman Perepelitsa]

On Wed, Apr 8, 2020 at 12:56 PM Ronald Fischer <ynnor@mm.st> wrote:
>
> > echo $'a$b\'c'
> >
> > This style allows a bit more interpolation than ordinary single quotes.
>
> My mistake: When I tried this first, it did not work, but I see that I had a typing error. I can get it working now.

I just tried it on the same system you are using just to be sure there
wasn't a bug back then. Works fine.

  zsh -f <<\END
    typeset -p ZSH_VERSION
    uname -sm
    echo $'a$b\'c'
  END

Output:

  typeset ZSH_VERSION=5.5.1
  CYGWIN_NT-10.0 x86_64
  a$b'c

This works the same way as in Bash, by the way.

Roman.