X-Git-Url: https://git.dlugolecki.net.pl/?a=blobdiff_plain;ds=sidebyside;f=doc%2Fusage.html;h=ee3e248bae1331b1f9d175c2320c416ef024881d;hb=e4ccfb6a6f26881db3874841a5aa2c2201a9c4e0;hp=409ebbf308878bf17f0b2726ade6faf57a8eedb3;hpb=43c83792bc560e33abb7eeea683f86bbcc7627ce;p=gedcom-parse.git diff --git a/doc/usage.html b/doc/usage.html index 409ebbf..ee3e248 100644 --- a/doc/usage.html +++ b/doc/usage.html @@ -1,615 +1,809 @@
libgedcom.so
), to be linked in the application
- programgedcom.h
), to be used in the sources
- of the application programgedcom-tags.h
) that is also installed,
- but that is automatically included via gedcom.h
libgedcom.so
), to be linked in the
+application program, which implements the callback parsergedcom.h
), to be used in the sources
+ of the application programgedcom-tags.h
) that is also installed,
+ but that is automatically included via gedcom.h
libgedcom.so
is also needed in this case, because the object model uses the callback parser internally):libgedcom_gom.so
), to be linked in the application program, which implements the C object modelgom.h
), to be used in the sources of the application program$PREFIX/share/gedcom-parse
- that contains some additional stuff, but which is not immediately
-important at first. I'll leave the description of the data directory
-for later.$PREFIX/share/gedcom-parse
+ that contains some additional stuff, but which is not immediately
+ important at first. I'll leave the description of the data directory
+ for later.gedcom.h
header is assumed, as everywhere
+in this manual):int result;
- ...
- result = gedcom_parse_file("myfamily.ged");
-
- Although this will not provide much information, one thing it does
-is parse the entire file and return the result. The function returns
-0 on success and 1 on failure. No other information is available using
- this function only.- In the above piece of code,void my_message_handler (Gedcom_msg_type type, - char *msg)
- {
- ...
- }
- ...
- gedcom_set_message_handler(my_message_handler);
- ...
- result = gedcom_parse_file("myfamily.ged");
-
my_message_handler
is the callback
- that will be called for errors (type=ERROR
), warnings (type=WARNING
) and messages (type=MESSAGE
). The
- callback must have the signature as in the example. For errors, the
- msg
passed to the callback will have the format:- Note that the entire string will be properly internationalized, and -encoded in UTF-8 (Why UTF-8?). Also, -no newline is appended, so that the application program can use it in any -way it wants. Warnings are similar, but use "Warning" instead of -"Error". Messages are plain text, without any prefix.Error on line
<lineno>: <actual_message>
-
-printf
is used in the message handler.gedcom.h
and gom.h
is required):int result;
+ ...
+ gedcom_init();
+ ...
+ result = gom_parse_file("myfamily.ged");
+
+The call to gom_parse_file
will build the C object model, which is then a complete representation of the GEDCOM file.gedcom_init
() should be one of the first calls
+in your program. The requirement is that it should come before the first
+call to iconv_open
(part of the generic character set conversion
+feature) in the program, either by your program itself, or indirectly by
+the library calls it makes. Practically, it should e.g. come before
+ any calls to any GTK functions, because GTK uses iconv_open
+ in its initialization.-lgedcom
option
+on the linking of the program as the last option, so that its initialization
+code is run first. In the case of using the C object model, the linking
+options should be: -lgedcom_gom -lgedcom
gom_parse_file
would be called in case the C object model is used):+ In the above piece of code,void my_message_handler (Gedcom_msg_type type, + char *msg)
+ {
+ ...
+ }
+ ...
+ gedcom_set_message_handler(my_message_handler);
+ ...
+ result = gedcom_parse_file("myfamily.ged");
+
my_message_handler
is the
+ callback that will be called for errors (type=ERROR
), warnings
+ (type=WARNING
) and messages (type=MESSAGE
). The
+ callback must have the signature as in the example. For errors,
+the msg
passed to the callback will have the format:+ Note that the entire string will be properly internationalized, and + encoded in UTF-8 (Why UTF-8?). Also, +no newline is appended, so that the application program can use it in any +way it wants. Warnings are similar, but use "Warning" instead of "Error". + Messages are plain text, without any prefix.Error on line
<lineno>: <actual_message>
+
+ printf
is used in the message handler.- Using theGedcom_ctxt my_header_start_cb (int level, -
- - Gedcom_val xref,
- - char *tag,
- - char *raw_value,
- - int parsed_tag,
- - Gedcom_val parsed_value)
- {
- printf("The header starts\n");
- return (Gedcom_ctxt)1;
- }
-
- void my_header_end_cb (Gedcom_ctxt self)
- {
- printf("The header ends, context is %d\n", (int)self); /* context - will print as "1" */
- }
-
- ...
- gedcom_subscribe_to_record(REC_HEAD, my_header_start_cb, - my_header_end_cb);
- ...
- result = gedcom_parse_file("myfamily.ged");
-
gedcom_subscribe_to_record
function, the application
- requests to use the specified callbacks as start and end callback. The end
- callback is optional: you can pass NULL
if you are not interested
- in the end callback. The identifiers to use as first argument to
-the function (here REC_HEAD
) are described in the
- interface details.Gedcom_ctxt
type that is used as a result of the start
- callback and as an argument to the end callback is vital for passing context
- necessary for the application. This type is meant to be opaque; in
- fact, it's a void pointer, so you can pass anything via it. The important
- thing to know is that the context that the application returns in the start
- callback will be passed in the end callback as an argument, and as we will
- see shortly, also to all the directly subordinate elements of the record.tag
is the GEDCOM tag in string format, the parsed_tag
- is an integer, for which symbolic values are defined as TAG_HEAD,
- TAG_SOUR,
TAG_DATA,
... and USERTAG
- for the application-specific tags. These values are defined in the
- header gedcom-tags.h
that is installed, and included via
- gedcom.h
(so no need to include gedcom-tags.h
yourself).struct
(or an object in a C++ application) that will contain the information for the
- header. In the end callback, the application could then e.g. do some
- finalizing operations on the struct
to put it in its database.Gedcom_val
type for the xref
- and parsed_value
arguments was not discussed, see further
-for this)- The subscription mechanism for elements is similar, only the signatures - of the callbacks differ. The signature for the start callback shows - that the context of the parent line (here e.g. theGedcom_ctxt my_header_source_start_cb(Gedcom_ctxt - parent,
- - int - level,
- - char* - tag,
- - char* - raw_value,
- - int - parsed_tag,
- - Gedcom_val - parsed_value)
- {
- char *source = GEDCOM_STRING(parsed_value);
- printf("This file was written by %s\n", source);
- return parent;
- }
-
- void my_header_source_end_cb(Gedcom_ctxt parent,
- - Gedcom_ctxt self,
- - Gedcom_val parsed_value)
- {
- printf("End of the source description\n");
- }
-
- ...
- gedcom_subscribe_to_element(ELT_HEAD_SOUR,
- - my_header_source_start_cb,
- - my_header_source_end_cb);
- ...
- result = gedcom_parse_file("myfamily.ged");
-
struct
that
-describes the header) is passed to this start callback. The callback
-itself returns here in this example the same context, but this can be its own context object
-of course. The end callback is called with both the context of the
-parent and the context of itself, which in this example will be the same.
- Again, the list of identifiers to use as a first argument for the
-subscription function are detailed in the
- interface details .Gedcom_val
type is meant to be an opaque type. The
- only thing that needs to be known about it is that it can contain specific
- data types, which have to be retrieved from it using pre-defined macros.
- These data types are described in the
- interface details. Gedcom_val
argument of the end callback
- is currently not used. It is there for future enhancements.Gedcom_val
arguments in
-the start callback for records. The first one (xref
) contains the xref_value
corresponding to the cross-reference (or NULL
if there isn't one), the second one (parsed_value
) contains the value that is parsed from the raw_value
. See the interface details.- This callback has a similar signature as the previous ones, - but it doesn't contain a parsed value. However, it does contain the - parent context, that was returned by the application for the most specific - containing tag that the application supported.void my_default_cb (Gedcom_ctxt parent, - int level, char* tag, char* raw_value, int parsed_tag)
- {
- ...
- }
+ After this introduction, let's see what the API looks like...
+
+ +Start and end callbacks
+ +Callbacks for records
+ As a simple example, we will get some information from the header +of a GEDCOM file. First, have a look at the following piece of code:
+
+ +Gedcom_ctxt my_header_start_cb (Gedcom_rec rec,
+ int level,
+ + Gedcom_val xref,
+ + char *tag,
+ + char *raw_value,
+ + int parsed_tag,
+ + Gedcom_val parsed_value)
+ {
+ printf("The header starts\n");
+ return (Gedcom_ctxt)1;
+ }
- ...
- gedcom_set_default_callback(my_default_cb);
- ...
- result = gedcom_parse_file("myfamily.ged");
+ void my_header_end_cb (Gedcom_rec rec, Gedcom_ctxt self)
+ {
+ printf("The header ends, context is %d\n", (int)self); + /* context will print as "1" */
+ }
+
+ ...
+ gedcom_subscribe_to_record(REC_HEAD, my_header_start_cb, + my_header_end_cb);
+ ...
+ result = gedcom_parse_file("myfamily.ged");
gedcom_subscribe_to_record
function, the
+ application requests to use the specified callbacks as start and end
+callback. The end callback is optional: you can pass NULL
+ if you are not interested in the end callback. The identifiers
+to use as first argument to the function (here REC_HEAD
)
+are described in the interface
+details . These are also passed as first argument in the callbacks (the Gedcom_rec
argument).- Note that the default callback will be called for any tag that isn't -specifically subscribed upon by the application, and can thus be called -in various contexts. For simplicity, the example above doesn't take -this into account (thestruct header {
- char* source;
- ...
- char* extra_text;
- };
-
- Gedcom_ctxt my_header_start_cb(int level, Gedcom_val xref, char* tag, -char *raw_value,
- - int parsed_tag, Gedcom_val parsed_value)
- {
- struct header head = my_make_header_struct();
- return (Gedcom_ctxt)head;
- }
+ From the name of the function it becomes clear that this function +is specific to complete records. For the separate elements in records + there is another function, which we'll see shortly. Again, the callbacks + need to have the signatures as shown in the example.
+
+ TheGedcom_ctxt
type that is used as a result of the +start callback and as an argument to the end callback is vital for passing +context necessary for the application. This type is meant to be opaque; +in fact, it's a void pointer, so you can pass anything via it. The +important thing to know is that the context that the application returns +in the start callback will be passed in the end callback as an argument, +and as we will see shortly, also to all the directly subordinate elements +of the record.
+
+ Thetag
is the GEDCOM tag in string format, theparsed_tag
+ is an integer, for which symbolic values are defined asTAG_HEAD,
+TAG_SOUR,
TAG_DATA,
... andUSERTAG +
for the application-specific tags. These values +are defined in the header
gedcom-tags.h
that is installed, +and included viagedcom.h
(so no need to includegedcom-tags.h
+ yourself).
+
+ The example passes a simple integer as context, but an application + could e.g. pass astruct
(or an object in a C++ application) + that will contain the information for the header. In the end callback, + the application could then e.g. do some finalizing operations on the +struct
to put it in its database.
+
+ (Note that theGedcom_val
type for thexref
+ andparsed_value
arguments was not discussed, see further + for this)
+
+ +Callbacks for elements
+ We will now retrieve the SOUR field (the name of the program that +wrote the file) from the header:
+ +Gedcom_ctxt my_header_source_start_cb(Gedcom_elt elt,
+ + Gedcom_ctxt + parent,
+ + int + level,
+ + char* + tag,
+ + char* + raw_value,
+ + int + parsed_tag,
+ + Gedcom_val + parsed_value)
+ {
+ char *source = GEDCOM_STRING(parsed_value);
+ printf("This file was written by %s\n", source);
+ return parent;
+ }
- void my_default_cb(Gedcom_ctxt parent, int level, char* tag, char* raw_value, - int parsed_tag)
- {
- struct header head = (struct header)parent;
- my_header_add_to_extra_text(head, level, tag, raw_value);
- }
+ void my_header_source_end_cb(Gedcom_elt elt,
+ Gedcom_ctxt parent,
+ + Gedcom_ctxt self,
+ + Gedcom_val parsed_value)
+ {
+ printf("End of the source description\n");
+ }
- gedcom_set_default_callback(my_default_cb);
- gedcom_subscribe_to_record(REC_HEAD, my_header_start, NULL);
- ...
- result = gedcom_parse_file(filename);
+ ...
+ gedcom_subscribe_to_element(ELT_HEAD_SOUR,
+ + my_header_source_start_cb,
+ + my_header_source_end_cb);
+ ...
+ result = gedcom_parse_file("myfamily.ged");
parent
could be of different
-types, depending on the context).NULL
. This is e.g. the case if none of the "upper" tags has been subscribed upon.struct
+ that describes the header) is passed to this start callback. The
+ callback itself returns here in this example the same context, but this
+can be its own context object of course. The end callback is called
+with both the context of the parent and the context of itself, which in this
+example will be the same. Again, the list of identifiers to use as
+a first argument for the subscription function are detailed in the interface details . Again, these are passed as first argument in the callback (the Gedcom_elt
argument).Gedcom_val
type is meant to be an opaque type. The
+ only thing that needs to be known about it is that it can contain specific
+ data types, which have to be retrieved from it using pre-defined macros.
+ These data types are described in the interface details.
+ Gedcom_val
argument of the end callback
+ is currently not used. It is there for future enhancements.Gedcom_val
arguments
+ in the start callback for records. The first one (xref
+ ) contains the xref_value
corresponding to the cross-reference
+ (or NULL
if there isn't one), the second one (parsed_value
+ ) contains the value that is parsed from the raw_value
. See
+ the interface details
+ .+ This callback has a similar signature as the previous ones, + but it doesn't contain a parsed value. However, it does contain the + parent context, that was returned by the application for the most specific + containing tag that the application supported.void my_default_cb (Gedcom_elt elt, Gedcom_ctxt parent, int level, + char* tag, char* raw_value, int parsed_tag)
+ {
+ ...
+ }
+
+ ...
+ gedcom_set_default_callback(my_default_cb);
+ ...
+ result = gedcom_parse_file("myfamily.ged");
+
+ Note that the default callback will be called for any tag that isn't + specifically subscribed upon by the application, and can thus be called + in various contexts. For simplicity, the example above doesn't take + this into account (thestruct header {
+ char* source;
+ ...
+ char* extra_text;
+ };
+
+ Gedcom_ctxt my_header_start_cb(Gedcom_rec rec, int level, Gedcom_val xref, char* tag, + char *raw_value,
+ + int parsed_tag, Gedcom_val parsed_value)
+ {
+ struct header head = my_make_header_struct();
+ return (Gedcom_ctxt)head;
+ }
+
+ void my_default_cb(Gedcom_elt elt, Gedcom_ctxt parent, int level, char* tag, char* +raw_value, int parsed_tag)
+ {
+ struct header head = (struct header)parent;
+ my_header_add_to_extra_text(head, level, tag, raw_value);
+ }
+
+ gedcom_set_default_callback(my_default_cb);
+ gedcom_subscribe_to_record(REC_HEAD, my_header_start, NULL);
+ ...
+ result = gedcom_parse_file(filename);
+
parent
could be of different
+ types, depending on the context).NULL
. This is e.g. the case if none
+ of the "upper" tags has been subscribed upon.gom_parse_file()
. For this, an entire model based on C structs is used. These structs are documented here,
+and follow the GEDCOM syntax quite closely. Each of the records in
+a GEDCOM file are modelled by a separate struct, and some common sub-structures
+have their own struct definition.struct header* gom_get_header();
+struct submission* gom_get_submission();
+
+ +struct XXX* gom_get_first_XXX();
+struct XXX* gom_get_XXX_by_xref(char* xref);
+
The XXX stands for one of the following:+family,
individual, multimedia, note, repository, source, submitter, user_rec
.
+
next
member of the structs. This means that e.g. the following piece of code will traverse the linked list of family records:+Thestruct family* fam;
+
+for (fam = gom_get_first_family() ; fam ; fam = fam->next) {
+ ...
+}
+
next
member of the last element in the list is guaranteed to have the NULL
value.previous
member. But for implementation reasons the behaviour of this previous
member on the edges of the linked list will not be guaranteed, i.e. it can be circular or terminated with NULL
, no assumptions can be made in the application code.next
and previous
+member following the above conventions. This means that the following
+piece of code traverses all children of a family (see the details of the
+different structs here):+Note that all character strings in the object model are encoded in UTF-8 (Why UTF-8?).struct family* fam = ...;
+
+struct xref_list* xrl;
+for (xrl = fam->children ; xrl ; xrl = xrl->next) {
+ ...
+}
+
extra
(of type struct user_data*
).
+ This gathers all non-standard GEDCOM tags within the scope of the struct
+in a flat linked list, no matter what the internal structure of the non-standard
+tags is. Each element of the linked list has:- Thevoid gedcom_set_debug_level (int level, - FILE* trace_output)
-
level
can be one of the following values:trace_output
is NULL
, debugging information
- will be written to stderr
, otherwise the given file handle
-is used (which must be open).- Thevoid gedcom_set_error_handling (Gedcom_err_mech - mechanism)
-
mechanism
can be one of:IMMED_FAIL
: immediately fail the
-parsing on an error (this is the default)DEFER_FAIL
: continue parsing after
- an error, but return a failure code eventuallyIGNORE_ERRORS
: continue parsing
-after an error, return success always+ Thevoid gedcom_set_debug_level (int level, FILE* +trace_output)
+
level
can be one of the following values:trace_output
is NULL
, debugging information
+ will be written to stderr
, otherwise the given file handle
+ is used (which must be open).- The argument can be:void gedcom_set_compat_handling - (int enable_compat)
-
+ Thevoid gedcom_set_error_handling (Gedcom_err_mech + mechanism)
+
mechanism
can be one of:locale
mechanism (i.e. via the LANG
, LC_ALL
or LC_CTYPE
environment variables), which also controls the gettext
- mechanism in the application. IMMED_FAIL
: immediately fail
+the parsing on an error (this is the default)DEFER_FAIL
: continue parsing
+after an error, but return a failure code eventuallyIGNORE_ERRORS
: continue parsing
+ after an error, return success alwaysgedcom-parse
contains an example implementation (utf8-locale.c
and utf8-locale.h
- in the top directory). Feel free to use it in
-your source code (it is not part of the library, and it isn't installed anywhere,
-so you need to take over the source and header file in your application).
- - -Both functions return a pointer to a static buffer that is overwritten on -each call. To function properly, the application must first set the -locale using thechar *convert_utf8_to_locale (char *input, int *conv_failures);
char *convert_locale_to_utf8 (char *input);
setlocale
function (the second step detailed below).
- All other steps given below, including setting up and closing down the conversion
-handles, are transparantly handled by the two functions. NULL
if you are not interested (note that usually, the interesting information is just whether there were
- conversion failures or not, which is then given by the integer being bigger
-than zero or not). The second function doesn't need this, because any
-locale can be converted to UTF-8.-void convert_set_unknown (const char *unknown);
-----#include <locale.h> /* for setlocale */
#include <langinfo.h> /* for nl_langinfo */
#include <iconv.h> /* for iconv_* functions */
-----setlocale(LC_ALL, "");
-----iconv_t iconv_handle;
...
iconv_handle = iconv_open(nl_langinfo(CODESET), "UTF-8");
if (iconv_handle == (iconv_t) -1)
/* signal an error */
-----/* char* in_buf is the input buffer, size_t in_len is its length */
/* char* out_buf is the output buffer, size_t out_len is its length */
size_t nconv;
char *in_ptr = in_buf;
char *out_ptr = out_buf;
nconv = iconv(iconv_handle, &in_ptr, &in_len, &out_ptr, &out_len);
If the output buffer is not big enough,-iconv
will return -1 and seterrno
toE2BIG
. Also, thein_ptr
andout_ptr
will point just after the last successfully converted character in the respective buffers, and thein_len
andout_len
will be updated to show the remaining lengths. There can be two strategies here:
--
-Another error case is when the conversion was unsuccessful (if one of the -characters can't be represented in the target character set). The- Make sure from the beginning -that the output buffer is big enough. However, it's difficult to find -an absolute maximum length in advance, even given the length of the input -string.
-
-
-- Do the conversion in several steps, growing the output buffer each time to make more space, and calling
-iconv
- consecutively until the conversion is complete. This is the preferred -way (a function could be written to encapsulate all this).iconv
function will then also return -1 and seterrno
toEILSEQ
; thein_ptr
will point to the character that couldn't be converted. In that case, again two strategies are possible:
--
-- Just fail the conversion, and show an error. This is not very user friendly, of course.
-
-
-- Skip over the character that can't be converted and append a "?" to the output buffer, then call
-iconv
again. Skipping over a UTF-8 character is fairly simple, as follows from the encoding rules:-
--
-- if the first byte is in binary 0xxxxxxx, then the character is only one byte long, just skip over that byte
-
-
-- if the first byte is in binary 11xxxxxx, then skip over that byte and all bytes 10xxxxxx that follow.
-
-
-- The example implementation -mentioned above grows the output buffer dynamically and outputs "?" for characters -that can't be converted.---iconv_close(iconv_handle);
- -There are three preprocessor symbols defined for version checks in the header:AC_CHECK_LIB(gedcom, gedcom_parse_file,,
- AC_MSG_ERROR(Cannot find libgedcom: Please install gedcom-parse))
-AC_MSG_CHECKING(for libgedcom version)
-AC_TRY_RUN([
-#include <stdio.h>
-#include <stdlib.h>
-#include <gedcom.h>
-int
-main()
-{
-if (GEDCOM_PARSE_VERSION >= 1034) exit(0);
-exit(1);
-}],
-ac_gedcom_version_ok='yes',
-ac_gedcom_version_ok='no',
-ac_gedcom_version_ok='no')
-if test "$ac_gedcom_version_ok" = 'yes' ; then
- AC_MSG_RESULT(ok)
-else
- AC_MSG_RESULT(not ok)
- AC_MSG_ERROR(You need at least version 1.34 of gedcom-parse)
-fi
-
GEDCOM_PARSE_VERSION_MAJOR
GEDCOM_PARSE_VERSION_MINOR
GEDCOM_PARSE_VERSION
(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.
$Id$- -
$Name$
+ + + This doesn't influence the generation of error or warning messages, + only the behaviour of the parser and its return code.
+ The argument can be:void gedcom_set_compat_handling (int enable_compat)
+
locale
mechanism (i.e. via the LANG
,
+ LC_ALL
or LC_CTYPE
environment variables), which also
+controls the gettext
mechanism in the application.
+gedcom-parse
contains an example implementation (utf8-locale.c
+ and utf8-locale.h
in the "t" subdirectory of the top directory).
+ Feel free to use it in your source code (it is not part of the library,
+and it isn't installed anywhere, so you need to take over the source and
+header file in your application). ++ Both functions return a pointer to a static buffer that is overwritten + on each call. To function properly, the application must first set +the locale using the+char *convert_utf8_to_locale (char *input, int *conv_failures);
char *convert_locale_to_utf8 (char *input);
setlocale
function (the second step detailed
+ below). All other steps given below, including setting up and closing
+ down the conversion handles, are transparantly handled by the two functions.
+ NULL
if you are not interested
+(note that usually, the interesting information is just whether there
+were conversion failures or not, which is then given by the integer
+being bigger than zero or not). The second function doesn't need this,
+because any locale can be converted to UTF-8.+++void convert_set_unknown (const char *unknown);
++ ++++#include <locale.h> /* for setlocale */
#include <langinfo.h> /* for nl_langinfo */
#include <iconv.h> /* for iconv_* functions */
++ ++++setlocale(LC_ALL, "");
++ ++++iconv_t iconv_handle;
...
iconv_handle = iconv_open(nl_langinfo(CODESET), "UTF-8");
if (iconv_handle == (iconv_t) -1)
/* signal an error */
++ ++++/* char* in_buf is the input buffer, size_t in_len is its length */
/* char* out_buf is the output buffer, size_t out_len is its length */
size_t nconv;
char *in_ptr = in_buf;
char *out_ptr = out_buf;
nconv = iconv(iconv_handle, &in_ptr, &in_len, &out_ptr, &out_len);
If the output buffer is not big enough,+ +iconv
will + return -1 and seterrno
toE2BIG
. Also, +thein_ptr
andout_ptr
will point just after +the last successfully converted character in the respective buffers, and +thein_len
andout_len
will be updated to show +the remaining lengths. There can be two strategies here:
+ ++
+ Another error case is when the conversion was unsuccessful (if one of +the characters can't be represented in the target character set). The +- Make sure from the beginning + that the output buffer is big enough. However, it's difficult to find + an absolute maximum length in advance, even given the length of the input + string.
+
+
+- Do the conversion in several + steps, growing the output buffer each time to make more space, and calling +
+ +iconv
consecutively until the conversion is complete. + This is the preferred way (a function could be written to encapsulate + all this).iconv
function will then also return -1 and seterrno
+ toEILSEQ
; thein_ptr
will point to the character + that couldn't be converted. In that case, again two strategies are +possible:
+ ++
+ +- Just fail the conversion, +and show an error. This is not very user friendly, of course.
+
+
+- Skip over the character that + can't be converted and append a "?" to the output buffer, then call
+ ++ iconv
again. Skipping over a UTF-8 character is fairly simple, + as follows from the encoding rules + :+ +
++
+ +- if the first byte is in +binary 0xxxxxxx, then the character is only one byte long, just skip over +that byte
+
+
+- if the first byte is in +binary 11xxxxxx, then skip over that byte and all bytes 10xxxxxx that follow.
+ +
+
++ The example implementation + mentioned above grows the output buffer dynamically and outputs "?" for characters + that can't be converted.+++iconv_close(iconv_handle);
+ There are three preprocessor symbols defined for version checks in the + header:AC_CHECK_LIB(gedcom, gedcom_parse_file,,
+ AC_MSG_ERROR(Cannot + find libgedcom: Please install gedcom-parse))
+ AC_MSG_CHECKING(for libgedcom version)
+ AC_TRY_RUN([
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <gedcom.h>
+ int
+ main()
+ {
+ if (GEDCOM_PARSE_VERSION >= 1034) exit(0);
+ exit(1);
+ }],
+ ac_gedcom_version_ok='yes',
+ ac_gedcom_version_ok='no',
+ ac_gedcom_version_ok='no')
+ if test "$ac_gedcom_version_ok" = 'yes' ; then
+ AC_MSG_RESULT(ok)
+ else
+ AC_MSG_RESULT(not ok)
+ AC_MSG_ERROR(You need at least version 1.34 of gedcom-parse)
+ fi
+
GEDCOM_PARSE_VERSION_MAJOR
GEDCOM_PARSE_VERSION_MINOR
GEDCOM_PARSE_VERSION
(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.
$Id$+ + +
$Name$
+ + +