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- <title>Using the GEDCOM parser library</title>
+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>Using the GEDCOM parser library</title>
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<h1 align="center">Using the GEDCOM parser library</h1>
<br>
<li><a href="#Start_and_end_callbacks">Start and end callbacks</a></li>
<li><a href="#Default_callbacks">Default callbacks</a></li>
+ </ul><li><a href="#Support_for_writing_GEDCOM_files">Support for writing GEDCOM files</a></li>
+ <ul>
+ <li><a href="#Opening_and_closing_files">Opening and closing files</a></li>
+ <li><a href="#Controlling_some_settings">Controlling some settings</a></li>
+ <li><a href="#Writing_data">Writing data</a><br>
+ </li>
</ul>
- <li><a href="#Other_API_functions">Other API functions</a></li>
+<li><a href="#Other_API_functions">Other API functions</a></li>
<ul>
<li><a href="#Debugging">Debugging</a></li>
</ul>
<li><a href="#Converting_character_sets">Converting character sets</a></li>
- <li><a href="#Support_for_configure.in">Support for configure.in</a><br>
+ <li><a href="#Support_for_configure.in">Development support</a><br>
+<br>
</li>
- <li><a href="interface.html">Interface details</a><br>
+ <li><a href="interface.html">Interface details of the callback parser</a></li><li><a href="gom.html">C object model</a><br>
</li>
+
</ul>
<hr width="100%" size="2">
<h2><a name="Overview"></a>Overview<br>
- </h2>
- The GEDCOM parser library is built as a callback-based parser (comparable
- to the SAX interface of XML). It comes with:<br>
+ </h2> The GEDCOM
+parser library provides two interfaces. At the one hand, it can be
+used as a callback-based parser (comparable to the SAX interface of
+XML); at the other hand, the parser can be used to convert the GEDCOM file
+into an object model (comparable to the DOM interface of XML). It comes
+with:<br>
<ul>
<li>a library (<code>libgedcom.so</code>), to be linked in the
-application program</li>
+application program, which implements the callback parser</li>
<li>a header file (<code>gedcom.h</code>), to be used in the sources
of the application program</li>
<li>a header file (<code>gedcom-tags.h</code>) that is also installed,
- but that is automatically included via <code>gedcom.h</code><br>
- </li>
+ but that is automatically included via <code>gedcom.h</code></li></ul>Additionally, if you want to use the GEDCOM C object model, the following should be used (note that <code>libgedcom.so</code> is also needed in this case, because the object model uses the callback parser internally):<br>
+<ul>
+ <li>a library (<code>libgedcom_gom.so</code>), to be linked in the application program, which implements the C object model</li>
+ <li>a header file (<code>gom.h</code>), to be used in the sources of the application program<br>
+ </li>
+
-</ul>
- Next to these, there is also a data directory in <code>$PREFIX/share/gedcom-parse</code>
+</ul>There is a separate script to help with library and compilation flags, see the <a href="#Support_for_configure.in">development support</a>.<br>
+<br>
+Next to these, there is also a data directory in <code>$PREFIX/share/gedcom-parse</code>
that contains some additional stuff, but which is not immediately
important at first. I'll leave the description of the data directory
for later.<br>
<br>
- The very simplest call of the gedcom parser is simply the following
- piece of code (include of the gedcom header is assumed, as everywhere
+ The very simplest call of the gedcom callback parser is simply the following
+ piece of code (include of the <code>gedcom.h</code> header is assumed, as everywhere
in this manual):<br>
<blockquote><code>int result;<br>
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.<br>
- <br>
- The call to <code>gedcom_init</code>() should be one of the first calls
+<br>
+Alternatively, programs using the C object model should use the following (in this case, the inclusion of both <code>gedcom.h</code> and <code>gom.h</code> is required):<br>
+
+<blockquote><code>int result;<br>
+ ...<br>
+ <b>gedcom_init</b>();<br>
+ ...<br>
+ result = <b>gom_parse_file</b>("myfamily.ged");<br>
+ </code> </blockquote>
+The call to <code>gom_parse_file</code> will build the C object model, which is then a complete representation of the GEDCOM file.<br>
+<br>
+No matter which of the interfaces you use, the call to <code>gedcom_init</code>() should be one of the first calls
in your program. The requirement is that it should come before the first
call to <code>iconv_open</code> (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 <code>iconv_open</code>
- in its initialization. For the same reason it is also advised to put
-the <code>-lgedcom</code> option on the linking of the program as the last
-option, so that it's initialization code is run first.<br>
- <br>
- The next sections will refine this piece of code to be able to have
+ in its initialization.<br>
+ <br>
+For the same reason it is also advised to put
+the <code>-lgedcom</code> 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: <code>-lgedcom_gom -lgedcom</code><br>
+ <br>The function <code>gedcom_init()</code> also initializes locale handling by calling <code>setlocale(LC_ALL, "")</code>, in case the application would not do this (it doesn't hurt for the application to do the same).<br>
+ <br>
+The next sections will refine this piece of code to be able to have
meaningful errors and the actual data that is in the file.<br>
<hr width="100%" size="2">
-<h2><a name="Error_handling"></a>Error handling</h2>
- Since this is a relatively simple topic, it is discussed before the
- actual callback mechanism, although it also uses a callback...<br>
- <br>
- The library can be used in several different circumstances, both
+<h2><a name="Error_handling"></a>Error handling</h2>The library can be used in several different circumstances, both
terminal-based as GUI-based. Therefore, it leaves the actual display
of the error message up to the application. For this, the application
needs to register a callback before parsing the GEDCOM file, which will
be called by the library on errors, warnings and messages.<br>
<br>
- A typical piece of code would be:<br>
+ A typical piece of code would be (<code>gom_parse_file</code> would be called in case the C object model is used):<br>
<blockquote><code>void <b>my_message_handler</b> (Gedcom_msg_type type,
char *msg)<br>
<hr width="100%" size="2">
<h2><a name="Data_callback_mechanism"></a>Data callback mechanism</h2>
The most important use of the parser is of course to get the data
-out of the GEDCOM file. As already mentioned, the parser uses a callback
- mechanism for that. In fact, the mechanism involves two levels.<br>
+out of the GEDCOM file. This section focuses on the callback mechanism (see <a href="gom.html">here</a> for the C object model). In fact, the mechanism involves two levels.<br>
<br>
The primary level is that each of the sections in a GEDCOM file is
notified to the application code via a "start element" callback and an
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:<br>
-<blockquote><code>Gedcom_ctxt <b>my_header_start_cb</b> (int level, <br>
+<blockquote><code>Gedcom_ctxt <b>my_header_start_cb</b> (Gedcom_rec rec,<br>
+ int level, <br>
Gedcom_val xref, <br>
return (Gedcom_ctxt)1;<br>
}<br>
<br>
- void <b>my_header_end_cb</b> (Gedcom_ctxt self)<br>
+ void <b>my_header_end_cb</b> (Gedcom_rec rec, Gedcom_ctxt self)<br>
{<br>
printf("The header ends, context is %d\n", (int)self);
/* context will print as "1" */<br>
if you are not interested in the end callback. The identifiers
to use as first argument to the function (here <code>REC_HEAD</code>)
are described in the <a href="interface.html#Record_identifiers"> interface
-details</a> .<br>
+details</a> . These are also passed as first argument in the callbacks (the <code>Gedcom_rec</code> argument).<br>
<br>
From the name of the function it becomes clear that this function
is specific to complete records. For the separate elements in records
We will now retrieve the SOUR field (the name of the program that
wrote the file) from the header:<br>
-<blockquote><code>Gedcom_ctxt <b>my_header_source_start_cb</b>(Gedcom_ctxt
+<blockquote><code>Gedcom_ctxt <b>my_header_source_start_cb</b>(Gedcom_elt elt,<br>
+
+ Gedcom_ctxt
parent,<br>
int
return parent;<br>
}<br>
<br>
- void <b>my_header_source_end_cb</b>(Gedcom_ctxt parent,<br>
+ void <b>my_header_source_end_cb</b>(Gedcom_elt elt,<br>
+ Gedcom_ctxt parent,<br>
Gedcom_ctxt self,<br>
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 <a
- href="interface.html#Element_identifiers"> interface details</a> .<br>
+a first argument for the subscription function are detailed in the <a href="interface.html#Element_identifiers"> interface details</a> . Again, these are passed as first argument in the callback (the <code>Gedcom_elt</code> argument).<br>
<br>
If we look at the other arguments of the start callback, we see the
level number (the initial number of the line in the GEDCOM file), the tag
The <code>Gedcom_val</code> 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 <a
- href="interface.html#Gedcom_val_types"> interface details</a>.
+ These data types are described in the <a href="interface.html#Gedcom_val_types"> interface details</a>.
<br>
<br>
Some extra notes:<br>
applications. To preserve this extra data anyway, a default callback
can be registered by the application, as in the following example:<br>
-<blockquote><code>void <b>my_default_cb</b> (Gedcom_ctxt parent, int level,
+<blockquote><code>void <b>my_default_cb</b> (Gedcom_elt elt, Gedcom_ctxt parent, int level,
char* tag, char* raw_value, int parsed_tag)<br>
{<br>
...<br>
char* extra_text;<br>
};<br>
<br>
- Gedcom_ctxt my_header_start_cb(int level, Gedcom_val xref, char* tag,
+ Gedcom_ctxt my_header_start_cb(Gedcom_rec rec, int level, Gedcom_val xref, char* tag,
char *raw_value,<br>
int parsed_tag, Gedcom_val parsed_value)<br>
return (Gedcom_ctxt)head;<br>
}<br>
<br>
- void my_default_cb(Gedcom_ctxt parent, int level, char* tag, char*
+ void my_default_cb(Gedcom_elt elt, Gedcom_ctxt parent, int level, char* tag, char*
raw_value, int parsed_tag)<br>
{<br>
struct header head = (struct header)parent;<br>
of the "upper" tags has been subscribed upon.<br>
+<hr width="100%" size="2"><br>
+<h2><a name="Support_for_writing_GEDCOM_files"></a>Support for writing GEDCOM files</h2>
+The Gedcom parser library also contains functions to writing GEDCOM files.
+ Similar as for the parsing itself, there are two interfaces: an interface
+which is very basic, and requires you to call a function for each line in
+the GEDCOM file, and an interface which just dumps the Gedcom object model
+to a file in one shot (if you use the Gedcom object model).<br>
+<br>
+Again, this section focuses on the basic interface, the Gedcom object model interface is described <a href="gom.html#Writing_the_object_model_to_file">here</a>.<br>
+<br>
+<h3><a name="Opening_and_closing_files"></a>Opening and closing files</h3>
+The basic functions for opening and closing Gedcom files for writing are the following:<br>
+<code></code>
+<blockquote><code>Gedcom_write_hndl <b>gedcom_write_open</b> (const char* filename);<br>
+int <b>gedcom_write_close</b> (Gedcom_write_hndl hndl, int* total_conv_fails);<br></code></blockquote>
+The function <code>gedcom_write_open</code> takes a parameter the name of
+the file to write, and returns a write handle, which needs to be used in
+subsequent functions. It returns <code>NULL</code> in case of errors.<br>
+<br>
+The function <code>gedcom_write_close</code> takes, next to the write handle,
+an integer pointer as parameter. If you pass an actual pointer for
+this, the function will write in it the total number of conversion failures;
+you can pass <code>NULL</code> if you're not interested. The function returns 0 in case of success, non-zero in case of failure.<br>
+<br>
+<h3><a name="Controlling_some_settings"></a>Controlling some settings<br>
+</h3>
+Note that by default the file is written in ASCII encoding (and hence e.g.
+accented characters will cause a conversion failure). You can change
+this by calling the following function <i>before</i> calling <code>gedcom_write_open</code>, i.e. it affects all files that are opened after it is being called:<code></code><code><br>
+</code>
+<blockquote><code>int <b>gedcom_write_set_encoding</b> (const char* charset, Encoding width, Enc_bom bom);<br></code></blockquote>
+The valid <code>charset</code> values are given in the first column in the file <code>gedcom.enc</code> in the data directory of gedcom-parse (<code>$PREFIX/share/gedcom-parse</code>).
+ The character sets UNICODE, ASCII and ANSEL are always supported (these
+are standard for GEDCOM), as well as ANSI (not standard), but there may be
+others.<br>
+<br>
+The <code>width</code> parameter takes one of the following values:<br>
+<ul>
+</ul>
+<ul>
+ <li><code><b>ONE_BYTE</b></code>: This should be used for all character sets except UNICODE.</li>
+ <li><code><b>TWO_BYTE_HILO</b></code>: High-low encoding for UNICODE (i.e. big-endian)</li>
+ <li><code><b>TWO_BYTE_LOHI</b></code>: Low-high encoding for UNICODE (i.e. little-endian)</li>
+</ul>
+The <code>bom</code> parameter determines whether a byte-order-mark should
+be written in the file in case of UNICODE encoding (usually preferred because
+it then clearly indicates the byte ordering). It takes one of the following
+values:<br>
+<ul>
+ <li><code><b>WITHOUT_BOM</b></code></li>
+ <li><code><b>WITH_BOM</b></code></li>
+</ul> For both these parameters you can pass 0 for non-UNICODE encodings,
+since that corresponds to the correct values (and is ignored anyway). The
+function returns 0 in case of success, non-zero in case of error. Note
+that you still need to pass the correct charset value for the HEAD.CHAR tag,
+otherwise you will get a warning, and the value will be forced to the correct
+value.<br>
+<br>
+Further, it is possible to control the kind of line terminator that is used, via the following function (also to be used before <code>gedcom_write_open</code>):<br>
+<blockquote><code>int <b>gedcom_write_set_line_terminator</b> (Enc_line_end end);<br></code></blockquote>
+The <code>end</code> parameter takes one of the following values:<br>
+<ul>
+ <li><b><code>END_CR</code></b>: only carriage return ("/r") (cf. Macintosh)</li>
+ <li><b><code>END_LF</code></b>: only line feed ("/n") (cf. Unix, Mac OS X)</li>
+ <li><b><code>END_CR_LF</code></b>: first carriage return, then line feed ("/r/n") (cf. DOS, Windows)</li>
+ <li><b><code>END_LF_CR</code></b>: first line feed, then carriage return ("/n/r")</li>
+</ul>
+By default, this is set to the appropriate line terminator on the current
+platform, so it only needs to be changed if there is some special reason
+for it.<br>
+<h3><a name="Writing_data"></a>Writing data<br>
+</h3>
+For actually writing the data, the principle is that every line in the GEDCOM
+file to write corresponds to a call to one of the following functions, except
+that CONT/CONC lines can be automatically taken care of. Note that
+the resulting GEDCOM file should conform to the GEDCOM standard. Several
+checks are built in already, and more will follow, to force this. There
+is (currently) no compatibility mode for writing GEDCOM files.<br>
+<br>
+In general, each of the following functions expect their input in UTF-8 encoding (see also <a href="#Converting_character_sets">here</a>). If this is not the case, errors will be returned.<br>
+<br>
+Note that for examples of using these functions you can look at the sources for the Gedcom object model (e.g. the function <code>write_header</code> in <code>gom/header.c</code>).<br>
+<h4>Records</h4>
+For writing lines corresponding to records (i.e. on level 0), the following function is available:
+<blockquote><code>int <b>gedcom_write_record_str</b> (Gedcom_write_hndl hndl, Gedcom_rec rec, char* xrefstr, char* value);<br></code></blockquote>
+The <code>hndl</code> parameter is the write handle that was returned by <code>gedcom_write_open</code>. The <code>rec</code> parameter is one of the identifiers given in the first column in <a href="interface.html#Record_identifiers">this table</a> (except <code>REC_USER</code>: see below). The <code>xrefstr</code> and <code>val</code> parameters are respectively the cross-reference key of the record (something like '<code>@FAM01@</code>'), and the value of the record line, which should be <code>NULL</code> for some record types, according to the same table.<br>
+<h4>Elements</h4>
+For writing lines corresponding to elements (inside records, i.e. on a level
+bigger than 0), the following functions are available, depending on the data
+type:
+<blockquote><code>int <b>gedcom_write_element_str</b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, char* value);<br>
+i</code><code>nt <b>gedcom_write_element_xref</b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, struct xref_value*
+value);</code><br>
+ <code>int <b>gedcom_write_element_date</b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, struct date_value*
+value);</code><br>
+ <code>i</code><code>nt <b>gedcom_write_element_age </b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, struct age_value*
+value);</code><br>
+</blockquote>
+<blockquote><code></code></blockquote>
+These functions only differ in the type of the last argument, which is the value of the element.<br>
+<br>
+The <code>hndl</code> parameter is again the write handle returned by <code>gedcom_write_open</code>. The <code>elt</code> parameter is one of the identifiers given in the first column in <a href="interface.html#Element_identifiers">this table</a> (except <code>ELT_USER</code>: see below). The <code>parent_rec_or_elt</code> is the corresponding <code>rec</code> or <code>elt</code>
+identifier of the logically enclosing statement: this will determine the
+level number written on the line, as the level number of the parent + 1.<br>
+<br>
+Some of the identifiers can actually stand for different tags. For this reason, the <code>parsed_tag</code> has to be passed for some of them. This parsed tag is the same as was returned by the callback functions defined <a href="#Start_and_end_callbacks">above</a>, and is an identifier of the form <code>TAG_<i>name</i></code>. This parameter is needed whenever the second column in <a href="interface.html#Element_identifiers">this table</a> shows several possible tags (this is e.g. the case for <code>ELT_SUB_FAM_EVT</code>).<br>
+<br>
+Note that for writing a date value, the given value should be valid, i.e.
+all its struct fields filled in properly and consistent. This can be
+done by calling <code>gedcom_normalize_date</code> (see <a href="interface.html#date">here</a>).<br>
+<h4>User-defined tags</h4>
+For user-defined tags (tags starting with an underscore), there are separate functions, again depending on the data type:<code></code>
+<blockquote><code>int <b>gedcom_write_user_str</b> (Gedcom_write_hndl hndl, int level, char* tag, char* xrefstr,<br>
+ char* value);<br>
+i</code><code>nt <b>gedcom_write_user_xref</b> (Gedcom_write_hndl hndl, </code><code>int level, char* tag, char* xrefstr,</code><br>
+ <code>
+ struct xref_value* value);</code><br>
+ <code></code></blockquote>
+In the case of user-defined tags, the level and tag string are passed verbatim
+(not controlled by the library). This allows to write any extra data
+that doesn't use a standard tag, but is only allowed for tags starting with
+an underscore.<br>
<hr width="100%" size="2">
<h2><a name="Other_API_functions"></a>Other API functions<br>
</h2>
- Although the above describes the basic interface of libgedcom, there
+
+ Although the above describes the basic interface of the gedcom parser, there
are some other functions that allow to customize the behaviour of the library.
These will be explained in the current section.<br>
the <code>locale</code> mechanism (i.e. via the <code>LANG</code>, <code>
LC_ALL</code> or <code>LC_CTYPE</code> environment variables), which also
controls the <code>gettext</code> mechanism in the application. <br>
- <br>
- <br>
-
- The source distribution of <code>
-gedcom-parse</code> contains an example implementation (<code>utf8-locale.c</code>
- and <code> utf8-locale.h</code> 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). <br>
- <br>
- Its interface is:<br>
-
-<blockquote>
- <pre><code>char *<b>convert_utf8_to_locale</b> (char *input, int *conv_failures);<br>char *<b>convert_locale_to_utf8</b> (char *input);<br></code></pre>
- </blockquote>
- 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 <code>setlocale</code> 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.
- <br>
- <br>
- If you pass a pointer to an integer to the first function, it will be
-set to the number of conversion failures, i.e. characters that couldn't
-be converted; you can also just pass <code>NULL</code> if you are not interested
-(note that usually, the interesting information is just whether there <i>
-were</i> 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.<br>
- <br>
- You can change the "?" that is output for characters that can't be converted
- to any string you want, using the following function before the conversion
- calls:<br>
-
-<blockquote>
- <pre><code>void <b>convert_set_unknown</b> (const char *unknown);</code></pre>
- </blockquote>
- <br>
- If you want to have your own functions for it instead of this example
-implementation, the following steps need to be taken by the application
-(more detailed info can be found in the info file of the GNU libc library
-in the "Generic Charset Conversion" section under "Character Set Handling"
-or online <a
- href="http://www.gnu.org/manual/glibc-2.2.3/html_chapter/libc_6.html#SEC99">
- here</a>):<br>
-
-<ul>
- <li>inclusion of some headers:</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>#include <locale.h> /* for setlocale */<br>#include <langinfo.h> /* for nl_langinfo */<br>#include <iconv.h> /* for iconv_* functions */<br></code></pre>
- </blockquote>
- </blockquote>
-
-<ul>
- <li>set the program's current locale to what
-the user configured in the environment:</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>setlocale(LC_ALL, "");</code><br></pre>
- </blockquote>
- </blockquote>
-
-<ul>
- <li>open a conversion handle for conversion
- from UTF-8 to the character set of the current locale (once for the entire
- program):</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>iconv_t iconv_handle;<br>...<br>iconv_handle = iconv_open(nl_langinfo(CODESET), "UTF-8");</code><br>if (iconv_handle == (iconv_t) -1)<br> /* signal an error */<br></pre>
- </blockquote>
- </blockquote>
-
-<ul>
- <li>then, every string can be converted
- using the following:</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>/* char* in_buf is the input buffer, size_t in_len is its length */<br>/* char* out_buf is the output buffer, size_t out_len is its length */<br><br>size_t nconv;<br>char *in_ptr = in_buf;<br>char *out_ptr = out_buf;<br>nconv = iconv(iconv_handle, &in_ptr, &in_len, &out_ptr, &out_len);</code></pre>
- </blockquote>
- </blockquote>
-
-<blockquote>If the output buffer is not big enough, <code>iconv</code> will
- return -1 and set <code>errno</code> to <code>E2BIG</code>. Also,
-the <code>in_ptr</code> and <code>out_ptr</code> will point just after
-the last successfully converted character in the respective buffers, and
-the <code> in_len</code> and <code>out_len</code> will be updated to show
-the remaining lengths. There can be two strategies here:<br>
-
- <ul>
- <li>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.<br>
- <br>
- </li>
- <li>Do the conversion in several
- steps, growing the output buffer each time to make more space, and calling
- <code>iconv</code> consecutively until the conversion is complete.
- This is the preferred way (a function could be written to encapsulate
- all this).</li>
-
- </ul>
- Another error case is when the conversion was unsuccessful (if one of
-the characters can't be represented in the target character set). The
- <code> iconv</code> function will then also return -1 and set <code>errno</code>
- to <code>EILSEQ</code>; the <code>in_ptr</code> will point to the character
- that couldn't be converted. In that case, again two strategies are
-possible:<br>
-
- <ul>
- <li>Just fail the conversion,
-and show an error. This is not very user friendly, of course.<br>
- <br>
- </li>
- <li>Skip over the character that
- can't be converted and append a "?" to the output buffer, then call <code>
- iconv</code> again. Skipping over a UTF-8 character is fairly simple,
- as follows from the <a
- href="http://www.cl.cam.ac.uk/%7Emgk25/unicode.html#utf-8">encoding rules</a>
- :</li>
-
- </ul>
-
- <ol>
-
- <ol>
- <li>if the first byte is in
-binary 0xxxxxxx, then the character is only one byte long, just skip over
-that byte<br>
- <br>
- </li>
- <li>if the first byte is in
-binary 11xxxxxx, then skip over that byte and all bytes 10xxxxxx that follow.<br>
- </li>
-
- </ol>
-
- </ol>
- </blockquote>
-
-<ul>
- <li>eventually, the conversion
-handle needs to be closed (when the program exits):<br>
- </li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>iconv_close(iconv_handle);<br></code></pre>
- </blockquote>
- </blockquote>
- The example implementation
- mentioned above grows the output buffer dynamically and outputs "?" for characters
- that can't be converted.<br>
+ <br>With<code>
+gedcom-parse</code> comes a library implementing help functions for UTF-8 encoding (<code></code>see
+the <a href="utf8tools.html">documentation</a> for this library).<br>
<hr width="100%" size="2">
-<h2><a name="Support_for_configure.in"></a>Support for configure.in</h2>
- Programs using the GEDCOM parser library and using autoconf to configure
- their sources can use the following statements in configure.in (the example
- is checking for gedcom-parse, version 1.34):<br>
-
-<blockquote><code>AC_CHECK_LIB(gedcom, gedcom_parse_file,,<br>
- AC_MSG_ERROR(Cannot
- find libgedcom: Please install gedcom-parse))<br>
- AC_MSG_CHECKING(for libgedcom version)<br>
- AC_TRY_RUN([<br>
- #include <stdio.h><br>
- #include <stdlib.h><br>
- #include <gedcom.h><br>
- int<br>
- main()<br>
- {<br>
- if (GEDCOM_PARSE_VERSION >= 1034) exit(0);<br>
- exit(1);<br>
- }],<br>
- ac_gedcom_version_ok='yes',<br>
- ac_gedcom_version_ok='no',<br>
- ac_gedcom_version_ok='no')<br>
- if test "$ac_gedcom_version_ok" = 'yes' ; then<br>
- AC_MSG_RESULT(ok)<br>
- else<br>
- AC_MSG_RESULT(not ok)<br>
- AC_MSG_ERROR(You need at least version 1.34 of gedcom-parse)<br>
- fi</code><br>
- </blockquote>
- There are three preprocessor symbols defined for version checks in the
- header:<br>
+<h2><a name="Support_for_configure.in"></a>Development support</h2>
+<h3>Macro for configure.in<br>
+</h3>
+There
+is a macro available for use in configure.in for applications that are using
+autoconf to configure their sources. The following macro checks whether
+the Gedcom parser library is available and whether its version is high enough:<br>
+<blockquote><code>AM_PATH_GEDCOM_PARSER([<i>min_version</i>,[<i>action_if_found</i>,[<i>action_if_not_found,</i>[<i>modules</i>]]]])</code><br>
+</blockquote>
+All the arguments are optional and default to 0. E.g. to check for
+version 1.34.2, you would put in configure.in the following statement:<br>
+<blockquote><code>AM_PATH_GEDCOM_PARSER(1.34.2)</code><br>
+</blockquote>Note that version numbers now contains three parts (since version
+0.20.0: this is also the first version in which this macro is available).<br>
+<br>
+The macro also sets the variables <code>GEDCOM_CFLAGS</code> and <code>GEDCOM_LIBS</code> for use in Makefiles. Typically, this would be done as follows in a Makefile.am:<br>
+<blockquote><code>bin_programs = myprg</code><br>
+ <code>myprg_SOURCES = myprg.c foo.c bar.c<br>
+INCLUDES = @GEDCOM_CFLAGS@<br>
+LDADD = @GEDCOM_LIBS@</code></blockquote>
+If your program uses some extra modules, they can be passed as fourth argument
+in the macro, so that the CFLAGS and LIBS are correctly filled in. Currently,
+the only available module is <code>gom</code> (the Gedcom object model). For example:<br>
+<blockquote><code>AM_PATH_GEDCOM_PARSER(0.21.2, , ,gom)</code><br>
+</blockquote>
+To be able to use this macro in the sources of your application, you have three options:<br>
+<ul>
+ <li>Put the file <code>m4/gedcom.m4</code> in your autoconf data directory (i.e. the path given by '<code>aclocal --print-ac-dir</code>', usually <code>/usr/share/aclocal</code>). You can do this automatically by going into the m4 subdirectory and typing '<code>make install-m4</code>'.<br>
+ <br>
+ </li>
+ <li>If you're using autoconf, but not automake, copy the contents of <code>m4/gedcom.m4</code> in the <code>aclocal.m4</code> file in your sources.<br>
+ <br>
+ </li>
+ <li>If you're using automake, copy the contents of <code>m4/gedcom.m4</code> in the <code>acinclude.m4</code> file in your sources.<br>
+ </li>
+</ul>
+<br>
+There are three preprocessor symbols defined for version checks in the
+ header (but their direct use is deprecated: please use the macro above):<br>
<ul>
<li><code>GEDCOM_PARSE_VERSION_MAJOR</code></li>
</li>
</ul>
- The last one is equal to <code>(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.</code><br>
+ The last one is equal to <code>(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.</code> As you see, this only checked the major and minor version, not the patch number, so this is obsolete.<br>
+<br>
+<h3>Compilation and linking flags</h3>
+Similar to other libraries, the GEDCOM parse library installs a script <code>gedcom-config</code> to help with compilation and linking flags for programs that don't use autoconf/automake.<br>
+<br>
+To get compilation flags for your program, use (depending on whether you
+only use the callback parser, or also the GEDCOM object model):
+<blockquote><code>gedcom-config --cflags<br>
+gedcom-config --cflags gom</code><br>
+</blockquote>
+Similarly, to get linking flags, use one of the following:
+<blockquote><code>gedcom-config --libs<br>
+gedcom-config --libs gom</code><br>
+</blockquote>
+
+
<hr width="100%" size="2">
<pre> </pre>
-</body>
-</html>
+<br>
+<br>
+<br>
+<br>
+<br>
+<br>
+<br>
+<br>
+<br>
+<br>
+</body></html>
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