I've got a regex that won't match under "use utf8". It works fine without utf8, so I had a look into the "use re debug" output to understand the difference and reason. But, I don't see it---could someone please explain?

This is our Perl: 

Summary of my perl5 (revision 5.0 version 6 subversion 1) configuratio
+n:

[download]
  Platform:
    osname=linux, osvers=2.4.18-3, archname=i386-linux
    uname='linux grcdg028 2.4.18-3 #1 thu apr 18 07:37:53 edt 2002 i68
+6 unknown '
    config_args='-des -Doptimize=-O2 -march=i386 -mcpu=i686 -Dcc=gcc -
+Dcf_by=Red Hat, Inc. -Dcccdlflags=-fPIC -Dinstallprefix=
sr -Dprefix=/usr -Darchname=i386-linux -Dvendorprefix=/usr -Dsiteprefi
+x=/usr -Uusethreads -Uuseithreads -Uuselargefiles -Dd_do
id -Dd_semctl_semun -Di_db -Di_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dm
+an3ext=3pm'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultipl
+icity=undef
    useperlio=undef d_sfio=undef uselargefiles=undef usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
  Compiler:
    cc='gcc', ccflags ='-fno-strict-aliasing -I/usr/local/include',
    optimize='-O2 -march=i386 -mcpu=i686',
    cppflags='-fno-strict-aliasing -I/usr/local/include'
    ccversion='', gccversion='2.96 20000731 (Red Hat Linux 7.3 2.96-11
+0)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=1
+2
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t',
+ lseeksize=4
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -ldl -lm -lc -lcrypt -lutil
    perllibs=-lnsl -ldl -lm -lc -lcrypt -lutil
    libc=/lib/libc-2.2.5.so, so=so, useshrplib=false, libperl=libperl.
+a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynami
+c'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'


Characteristics of this binary (from libperl):
  Compile-time options:
  Built under linux
  Compiled at Sep  3 2003 17:48:23
  @INC:
    /usr/lib/perl5/5.6.1/i386-linux
    /usr/lib/perl5/5.6.1
    /usr/lib/perl5/site_perl/5.6.1/i386-linux
    /usr/lib/perl5/site_perl/5.6.1
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/vendor_perl/5.6.1/i386-linux
    /usr/lib/perl5/vendor_perl/5.6.1
    /usr/lib/perl5/vendor_perl
    .

[download]
This is the regex and the debug output: 
Compiling REx `^((?x-ism: [^\?]*? ))/((?x-ism: [^/\?]*? ))$'

[download]
size 21 first at 2
   1: BOL(2)
   2: OPEN1(4)
   4:   MINMOD(5)
   5:   STAR(8)
   6:     ANYOFUTF8[^?...003f   003f](0)
   8: CLOSE1(10)
  10: EXACT </>(12)
  12: OPEN2(14)
  14:   MINMOD(15)
  15:   STAR(18)
  16:     ANYOFUTF8[^/?...002f  002f 003f       003f](0)
  18: CLOSE2(20)
  20: EOL(21)
  21: END(0)
floating `/' at 0..2147483647 (checking floating) anchored(BOL) minlen
+ 1
Guessing start of match, REx `^((?x-ism: [^\?]*? ))/((?x-ism: [^/\?]*?
+ ))$' against `pf1ad1%/pf2%2Fad2/pdad3/pfad4/filename'..Found floatin
+g substr `/' at offset 7...
Guessed: match at offset 0
Matching REx `^((?x-ism: [^\?]*? ))/((?x-ism: [^/\?]*? ))$' against `p
+f1ad1%/pf2%2Fad2/pdad3/pfad4/filename'
  Setting an EVAL scope, savestack=9
   0 <> <pf1ad1%/pf2%>    |  1:  BOL
   0 <> <pf1ad1%/pf2%>    |  2:  OPEN1
   0 <> <pf1ad1%/pf2%>    |  4:  MINMOD
   0 <> <pf1ad1%/pf2%>    |  5:  STAR
  Setting an EVAL scope, savestack=9
   0 <> <pf1ad1%/pf2%>    |  8:    CLOSE1
   0 <> <pf1ad1%/pf2%>    | 10:    EXACT </>
                              failed...
                           ANYOFUTF8[^?...003f  003f] can match 38 tim
+es out of 1...
  38 <ad4/filename> <>    |  8:    CLOSE1
  38 <ad4/filename> <>    | 10:    EXACT </>
                              failed...
                           ANYOFUTF8[^?...003f  003f] can match 0 time
+s out of 1...
                            failed...

[download]
Match failed

[download]
Thank you...

In reply to regex won't match with utf8 enabled... by Beechbone

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.