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Mailing List Message of <rpm-devel>

Re: Generalizing EVR comparison precedence, preliminaries

From: Ralf S. Engelschall <rse+rpm-devel@rpm5.org>
Date: Fri 02 Jan 2009 - 15:38:51 CET
Message-ID: <20090102143851.GA40484@engelschall.com>
On Fri, Jan 02, 2009, Jeff Johnson wrote:

> On Jan 2, 2009, at 8:04 AM, Jeff Johnson wrote:
>>
>> Hmmm, the PCRE posix emulation seems to *ahem* extend POSIX syntax
>> slightly then.
>
> A spot check with --miredebug seems to hint at a PCRE extension to POSIX
> emulation,
> the values in the output are what I would expect if using POSIX ERE's
> even though
> the pattern is PCRE:
>
> [jbj@wellfleet wdj]$ rpm -Va --nofiles --miredebug
> --> mireRegcomp(0xb9caeea0, "i386-redhat-linux-gnu") rc 0
> --> mireRegcomp(0xb9d9df30, "^(?:([^:-]+):)?([^:-]+)(?:-([^:-]+))?(?::
> ([^:-]+))?$") rc 0
> --> mireRegexec(0xb9d9df30, 0xb9cef036[7]) rc 0 mode 2 "3.0.4-1"
> --> mireRegexec(0xb9d9df30, 0xb9d9de60[7]) rc 0 mode 2 "3.0.4-1"
> --> mireRegexec(0xb9d9df30, 0xb9cef03e[5]) rc 0 mode 2 "4.0-1"
> --> mireRegexec(0xb9d9df30, 0xb9d9de94[5]) rc 0 mode 2 "4.0-1"
> --> mireRegexec(0xb9d9df30, 0xb9ceebfb[7]) rc 0 mode 2 "3.0.4-1"
> --> mireRegexec(0xb9d9df30, 0xb9d9de60[7]) rc 0 mode 2 "3.0.4-1"
> --> mireRegexec(0xb9d9df30, 0xb9ceec03[5]) rc 0 mode 2 "4.0-1"
> --> mireRegexec(0xb9d9df30, 0xb9d9de94[5]) rc 0 mode 2 "4.0-1"
> --> mireRegexec(0xb9d9df30, 0xb9ce1201[13]) rc 0 mode 2 "2.13.0-2.fc10"
> --> mireRegexec(0xb9d9df30, 0xb9cf028d[6]) rc 0 mode 2 "2.10.3"
>
> "Works" is all I really care. And I do appreciate any/all assistance
> with RE writing.

Well, the PCRE emulation of the POSIX regex API indeed is mainly about
the API and not the supported patterns. Nevertheless, it means RPM then
depends on the PCRE library and no longer can use a the POSIX regex API
of any other regex library (as those usually provide just the standard
POSIX patterns!). So, for me personally a fixed PCRE dependency is
harmless, as I always build RPM 5 with PCRE in OpenPKG. But I don't know
whether it is acceptable for others. OTOH, PCRE is a harmless little
library and it should not really harm if RPM has a mandatory dependency
to it IMHO...

                                       Ralf S. Engelschall
                                       rse@engelschall.com
                                       www.engelschall.com
Received on Fri Jan 2 15:40:09 2009
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