.TH LIBEXTRACTOR 3 "Sept 4, 2012" "GNU libextractor 1.0.0"
.SH NAME
libextractor \- meta\-information extraction library 1.0.0
.SH SYNOPSIS

\fB#include <extractor.h>

\fBconst char *EXTRACTOR_metatype_to_string (enum EXTRACTOR_MetaType \fItype\fB);

\fBconst char *EXTRACTOR_metatype_to_description (enum EXTRACTOR_MetaType \fItype\fB);

\fBenum EXTRACTOR_MetaTypeEXTRACTOR_metatype_get_max (void);

\fBstruct EXTRACTOR_PluginList *EXTRACTOR_plugin_add_defaults (enum EXTRACTOR_Options \fIflags\fB);

\fBstruct EXTRACTOR_PluginList *EXTRACTOR_plugin_add (struct EXTRACTOR_PluginList *\fIprev\fB, const char *\fIlibrary\fB, const char *\fIoptions\fB, enum EXTRACTOR_Options \fIflags\fB);


\fBstruct EXTRACTOR_PluginList *EXTRACTOR_plugin_add_last (struct EXTRACTOR_PluginList *\fIprev\fB, const char *\fIlibrary\fB, const char *\fIoptions\fB, enum EXTRACTOR_Options \fIflags\fB);

\fBstruct EXTRACTOR_PluginList *EXTRACTOR_plugin_add_config (struct EXTRACTOR_PluginList *\fIprev\fB, const char *\fIconfig\fB, enum EXTRACTOR_Options \fIflags\fB);
		
\fBstruct EXTRACTOR_PluginList *EXTRACTOR_plugin_remove (struct EXTRACTOR_PluginList *\fIprev\fB, const char *\fIlibrary\fB);

\fBvoid EXTRACTOR_plugin_remove_all (struct EXTRACTOR_PluginList *\fIplugins\fB);

\fBvoid EXTRACTOR_extract (struct EXTRACTOR_PluginList *\fIplugins\fB, const char *\fIfilename\fB, const void *\fIdata\fB, size_t \fIsize\fB, EXTRACTOR_MetaDataProcessor \fIproc\fB, void *\fIproc_cls\fB);

\fBint EXTRACTOR_meta_data_prin t(void *\fIhandle\fB, const char *\fIplugin_name\fB, enum EXTRACTOR_MetaType \fItype\fB, enum EXTRACTOR_MetaFormat \fIformat\fB, const char *\fIdata_mime_type\fB, const char *\fIdata\fB, size_t \fIdata_len\fB);

\fBEXTRACTOR_VERSION

.SH DESCRIPTION
.P
GNU libextractor is a simple library for keyword extraction.  libextractor does not support all formats but supports a simple plugging mechanism such that you can quickly add extractors for additional formats, even without recompiling libextractor.  libextractor typically ships with dozens of plugins that can be used to obtain meta data from common file-types.  If you want to write your own plugin for some filetype, all you need to do is write a little library that implements a single method with this signature:

 \fBvoid EXTRACTOR_XXX_extract_method (struct EXTRACTOR_ExtractContext *\fIec\fB);\fP

.P
\fIec\fP contains function pointers for reading, seeking, getting the overall file size and returning meta data.  There is also a field with options for the plugin.  New plugins will be automatically located and used once they are installed in the respective directory (typically something like /usr/lib/libextractor/).  
.P
The application \fBextract\fP gives an example how to use libextractor.
.P
The basic use of libextractor is to load the plugins (for example with \fBEXTRACTOR_plugin_add_defaults\fP), then to extract the keyword list using \fBEXTRACTOR_extract\fP, and finally unloading the plugins (with \fBEXTRACTOR_plugin_remove_all\fP).
.P
Textual meta data obtained from libextractor is supposed to be UTF-8 encoded if the text encoding is known.  Plugins are supposed to convert meta\-data to UTF\-8 if necessary.    The \fBEXTRACTOR_meta_data_print\fP function converts the UTF-8 keywords to the character set from the current locale before printing them.  
.P
.SH "SEE ALSO"
extract(1)

.SH "LEGAL NOTICE"
libextractor is released under the GPL and a GNU package (http://www.gnu.org/).

.SH BUGS
A couple of file-formats (on the order of 10^3) are not recognized...

.SH AUTHORS
extract was originally written by Christian Grothoff <christian@grothoff.org> and Vidyut Samanta <vids@cs.ucla.edu>. Use <libextractor@gnu.org> to contact the current maintainer(s).

.SH AVAILABILITY
You can obtain the original author's latest version from http://www.gnu.org/software/libextractor/.