/[pcre]/code/trunk/doc/pcre.txt

Diff of /code/trunk/doc/pcre.txt

Parent Directory | Revision Log | View Patch Patch

-revision 128 by ph10,
Tue Mar 20 11:46:50 2007 UTC
+revision 142 by ph10,
Fri Mar 30 15:55:18 2007 UTC
 Line 1323 
 STUDYING A PATTERN
  LOCALE SUPPORT
         PCRE handles caseless matching, and determines whether  characters  are
-        letters  digits,  or whatever, by reference to a set of tables, indexed
+        letters,  digits, or whatever, by reference to a set of tables, indexed
         by character value. When running in UTF-8 mode, this  applies  only  to
         characters  with  codes  less than 128. Higher-valued codes never match
         escapes such as \w or \d, but can be tested with \p if  PCRE  is  built
         with  Unicode  character property support. The use of locales with Uni-
-        code is discouraged.
+        code is discouraged. If you are handling characters with codes  greater
+        than  128, you should either use UTF-8 and Unicode, or use locales, but
-        An internal set of tables is created in the default C locale when  PCRE
+        not try to mix the two.
-        is  built.  This  is  used when the final argument of pcre_compile() is
-        NULL, and is sufficient for many applications. An  alternative  set  of
+        PCRE contains an internal set of tables that are used  when  the  final
-        tables  can,  however, be supplied. These may be created in a different
+        argument  of  pcre_compile()  is  NULL.  These  are sufficient for many
-        locale from the default. As more and more applications change to  using
+        applications.  Normally, the internal tables recognize only ASCII char-
-        Unicode, the need for this locale support is expected to die away.
+        acters. However, when PCRE is built, it is possible to cause the inter-
+        nal tables to be rebuilt in the default "C" locale of the local system,
-        External  tables  are  built by calling the pcre_maketables() function,
+        which may cause them to be different.
-        which has no arguments, in the relevant locale. The result can then  be
-        passed  to  pcre_compile()  or  pcre_exec()  as often as necessary. For
+        The  internal tables can always be overridden by tables supplied by the
-        example, to build and use tables that are appropriate  for  the  French
+        application that calls PCRE. These may be created in a different locale
-        locale  (where  accented  characters  with  values greater than 128 are
+        from  the  default.  As more and more applications change to using Uni-
+        code, the need for this locale support is expected to die away.
+        External tables are built by calling  the  pcre_maketables()  function,
+        which  has no arguments, in the relevant locale. The result can then be
+        passed to pcre_compile() or pcre_exec()  as  often  as  necessary.  For
+        example,  to  build  and use tables that are appropriate for the French
+        locale (where accented characters with  values  greater  than  128  are
         treated as letters), the following code could be used:
           setlocale(LC_CTYPE, "fr_FR");
           tables = pcre_maketables();
           re = pcre_compile(..., tables);
+        The  locale  name "fr_FR" is used on Linux and other Unix-like systems;
+        if you are using Windows, the name for the French locale is "french".
         When pcre_maketables() runs, the tables are built  in  memory  that  is
         obtained  via  pcre_malloc. It is the caller's responsibility to ensure
         that the memory containing the tables remains available for as long  as
-Line 2918 
 BACKSLASH
+Line 2928 
 BACKSLASH
         is a letter or digit. The definition of  letters  and  digits  is  con-
         trolled  by PCRE's low-valued character tables, and may vary if locale-
         specific matching is taking place (see "Locale support" in the  pcreapi
-        page).  For  example,  in  the  "fr_FR" (French) locale, some character
+        page).  For  example,  in  a French locale such as "fr_FR" in Unix-like
-        codes greater than 128 are used for accented  letters,  and  these  are
+        systems, or "french" in Windows, some character codes greater than  128
-        matched by \w.
+        are used for accented letters, and these are matched by \w.
         In  UTF-8 mode, characters with values greater than 128 never match \d,
         \s, or \w, and always match \D, \S, and \W. This is true even when Uni-
-Line 3289 
 SQUARE BRACKETS AND CHARACTER CLASSES
+Line 3299 
 SQUARE BRACKETS AND CHARACTER CLASSES
         If a range that includes letters is used when caseless matching is set,
         it matches the letters in either case. For example, [W-c] is equivalent
         to  [][\\^_`wxyzabc],  matched  caselessly,  and  in non-UTF-8 mode, if
-        character tables for the "fr_FR" locale are in use, [\xc8-\xcb] matches
+        character tables for a French locale are in  use,  [\xc8-\xcb]  matches
         accented  E  characters in both cases. In UTF-8 mode, PCRE supports the
         concept of case for characters with values greater than 128  only  when
         it is compiled with Unicode property support.

 Legend:



Removed from v.128
 


changed lines


 
Added in v.142
 Legend:



Removed from v.128
 


changed lines


 
Added in v.142
-Removed from v.128
+Added in v.142

	ViewVC Help
Powered by ViewVC 1.1.5