Re: Cannot change to 'C:\' (root) on Windows

[Juergen W. <wie...@fr...>]

Am Montag, 14. November 2005 09:45 schrieb Hans-Bernhard Broeker:
> Ethan A Merritt wrote:
> > It *would* be ended by the trailing single quote, if there were one.
> > But there is no such trailing single quote in your command line
> > because the only candidate has been escaped by a backslash.
>
> No, it's not supposed to be escaped.  At least not in any version up to
> 4.0 it wasn't.  There are no backslash escapes being processed on
> single-quoted strings in gnuplot, period.  See 'help syntax'.  Thus this
> behaviour:

"help syntax quotes" only says that there is no backslash processing
of special characters.  It does not state there is no special
meaning of backslashes at all.  At least, I cannot find it.

> > gnuplot> set title 'C:\'; foo' ; show title
> >         title is "C:\\'; foo", offset at ((character units) 0, 0, 0)
>
> Is a bug, and has been as long as it was present in the program.
>
> > The backslash character is always interpreted as an escape during input.
>
> Not inside single-quoted strings.
>
> > Single or double quotes make no difference.
>
> If so, that's a bug, or an incompatible change since version 4.0.  Proof
> from 4.0 on Win32:
>
> gnuplot> set label 1 "a\n\t\\\qb"
> gnuplot> set label 2 'a\n\t\\\qb'
> gnuplot> show lab
>
>      label 1 "a\n\t\\qb" at (0, 0, 0) left not rotated back  nopoint
>      label 2 "a\\n\\t\\\\\\qb" at (0, 0, 0) left not rotated back nopoint
>
> gnuplot>
>
> In other words: \-escape sequences in "" can become special characters
> like LF, TAB or the backslash itself, whereas \ characters in '' become
> literal \ characters, which 'show' doubles up since it uses "" strings.

The behaviour you show is exactly the same as raw strings in
python. [With the exception that gnuplot silently terminates strings
at the end of the line.]  Really.  Backslashes are used as escape
characters and nevertheless taken into the string.  It's insane.
But strictly speaking, it's not a bug.  And it has not changed since
3.7, AFAICS.


Juergen