# [RFC]strn(case)cmp supporting negative length as third parameter - Thread: https://externals.io/message/54226 - Original archive: https://news-web.php.net/php.internals/54226 - Started by Laruence on 2011-07-28T04:58:01+00:00 - Messages: 7 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #54226 — Laruence — 2011-07-28T04:58:01+00:00 URL: https://externals.io/message/54226#54226 Hi: strn(case)cmp dosen't support a negative length as its third paramter, while substr dose. I wrote a patch to make strn(case)cmp supporting negative length, make following script works as expect: here is the rfc: https://wiki.php.net/rfc/strncmpnegativelen any question? plz worte me back. thanks -- Laruence  Xinchen Hui http://www.laruence.com/ --- ## #54229 — Derick Rethans — 2011-07-28T10:59:55+00:00 URL: https://externals.io/message/54226#54229 · In reply to: #54226 > Hi: > > strn(case)cmp dosen't support a negative length as its third > paramter, while substr dose. > > I wrote a patch to make strn(case)cmp supporting negative length, > make following script works as expect: > > if (strncmp("prefix_num", "num", -3) === 0) { > echo "they have same suffix\n"; > } > ?> > > here is the rfc: https://wiki.php.net/rfc/strncmpnegativelen - You're changing binary API of some API functions, so this can't go into PHP 5.3: -ZEND_API int zend_binary_strncmp(const char *s1, uint len1, const char *s2, uint len2, uint length); +ZEND_API int zend_binary_strncmp(const char *s1, uint len1, const char *s2, uint len2, int length); cheers, Derick -- http://derickrethans.nl | http://xdebug.org Like Xdebug? Consider a donation: http://xdebug.org/donate.php twitter: @derickr and @xdebug --- ## #54230 — Laruence — 2011-07-28T11:32:46+00:00 URL: https://externals.io/message/54226#54230 · In reply to: #54229 Hi: why? I think this change would not cause any other side-effects. and if you are worry about INT_MAX, I think it's ok to declare with long(in fact, I already did so). thanks 2011/7/28 Derick Rethans : > > > > […] > > - You're changing binary API of some API functions, so this can't go >  into PHP 5.3: > >        -ZEND_API int zend_binary_strncmp(const char *s1, uint len1, const char *s2, uint len2, uint length); >        +ZEND_API int zend_binary_strncmp(const char *s1, uint len1, const char *s2, uint len2, int length); > > cheers, > Derick > > -- > http://derickrethans.nl | http://xdebug.org > Like Xdebug? Consider a donation: http://xdebug.org/donate.php > twitter: @derickr and @xdebug > -- Laruence  Xinchen Hui http://www.laruence.com/ --- ## #54231 — Pierre Joye — 2011-07-28T11:41:05+00:00 URL: https://externals.io/message/54226#54231 · In reply to: #54230 the signature is not the same anymore, some extension may not build anymore (depending on the compiler used and its flag). Cheers, > Hi: > > why? > > I think this change would not cause any other side-effects. > > and if you are worry about INT_MAX,  I think it's ok to declare with > long(in fact, I already did so). > > thanks > > 2011/7/28 Derick Rethans : > > […] > > > > -- > Laruence  Xinchen Hui > http://www.laruence.com/ > > -- > > > > -- Pierre @pierrejoye | http://blog.thepimp.net | http://www.libgd.org --- ## #54232 — Laruence — 2011-07-28T12:25:07+00:00 URL: https://externals.io/message/54226#54232 · In reply to: #54231 Hi: As Derick and Pierre said(in IRC), I change the patch base from PHP 5.3 to PHP5.4, and avoid changing ZEND_API declaration. RFC updated new patch : http://www.laruence.com/php-dev/php-5.4-trunk-strncmp-supproting-negative-len.patch thanks 2011/7/28 Pierre Joye : > the signature is not the same anymore, some extension may not build > anymore (depending on the compiler used and its flag). > > Cheers, > > > > […] > > > > -- > Pierre > > @pierrejoye | http://blog.thepimp.net | http://www.libgd.org > -- Laruence  Xinchen Hui http://www.laruence.com/ --- ## #54234 — keisial@gmail.com — 2011-07-28T18:20:34+00:00 URL: https://externals.io/message/54226#54234 · In reply to: #54226 Laruence wrote: > Hi: > > strn(case)cmp dosen't support a negative length as its third > paramter, while substr dose. > here is the rfc: https://wiki.php.net/rfc/strncmpnegativelen > > any question? plz worte me back. > > thanks What do you exactly mean by "in the reverse order" in > if the abs of the negative length is greater than any strlen of the > first two parameters, then strn(case)cmp will work as strncmp in the > reverse order with the abs value: Looking at > var_dump (strncmp ("prefix_num", "num", -10)); > //outpu: int(7) it seems to mean that it would be equivalent to > var_dump(strncmp("mun_xiferp", "mun", 10)); However, if I'm reading the patch correctly, it would be taking the smaller string. Ie. it would be equivalent to > var_dump (strncmp ("prefix_num", "num", -3)); Seems an implementation bug. --- ## #54242 — Laruence — 2011-07-29T01:08:32+00:00 URL: https://externals.io/message/54226#54242 · In reply to: #54234 Hi: first of all, yes , you are right about the reverse order thing: and then, they are not equal: will output: strncmp: int(5) int(5) int(0) int(0) thanks 2011/7/29 Ángel González : > Laruence wrote: > > […] > > > […] > > What do you exactly mean by "in the reverse order" in > > […] > > Looking at > > […] > > it seems to mean that it would be equivalent to > > […] > > However, if I'm reading the patch correctly, it would > be taking the smaller string. Ie. it would be equivalent > to > > > […] > > Seems an implementation bug. > > -- Laruence  Xinchen Hui http://www.laruence.com/