Re: [Exim] Possible bug in ${sg}

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Autor: Philip Hazel
Data:  
Dla: Tore Anderson
CC: exim-users
Temat: Re: [Exim] Possible bug in ${sg}
On 18 Dec 2002, Tore Anderson wrote:

> > exim -be '${sg{foo;bar\;baz\\;zot\\\;biff\\\\;bing}{\\\\*;}{\\\\\\;}}'
> >
> > The problem is, that first exim unescapes the \\ to \ then then pcre
> > will do so too, your string would result in
>
> Aha. I wonder why this behaviour isn't documented.


It is documented. From spec.txt:

${sg{<subject>}{<regex>}{<replacement>}}

   This item works like Perl's substitution operator (s) with the global (/g)
   option; hence its name. However, unlike the Perl equivalent, Exim does not  |
   modify the subject string; instead it returns the modified string for       |
   insertion into the overall expansion. The item takes three arguments: the   |
   subject string, a regular expression, and a substitution string. For
   example


     ${sg{abcdefabcdef}{abc}{xyz}}


   yields 'xyzdefxyzdef'. Because all three arguments are expanded before use,
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   if any $ or \ characters are required in the regular expression or in the
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   substitution string, they have to be escaped.
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


--
Philip Hazel            University of Cambridge Computing Service,
ph10@???      Cambridge, England. Phone: +44 1223 334714.