User Manual for iconverter

Author : Saumen Mandal (saumen@cse.iitk.ac.in)

History : First release :


	Code Transformations using iconverter
	-------------------------------------
	
	Support is provided for conversions from iscii code space to unicode and vice-versa
for each of the ten Indian languages. A file containing Indian language texts in ISCII codes, 
can be converted to its unicode equivalent with the help of the tool - iconverter.

The syntax for the above is :

	iconverter -e encoding_file iscii_coded_file_name unicode_file_name

For the conversion from unicode to iscii coded file the syntax is :

	iconverter -e encoding_file unicode_coded_file_name iscii_file_name 

  The encoding_file for the code conversions contains the mapping from one code space to another
and is different for different Indian languages. It is also different when converting from iscii
to unicode as against unicode to iscii for the same language.

  The encoding files come along with the isciilib package and get installed when isciilib is 
installed. The various encoding files are contained in the directory /usr/share/fonts/encodings/
An example command for conversion would be :

	iconverter -e iscii_unicode_dev dev.isc dev.uni

   This does the conversion of an iscii coded devanagari file to its equivalent unicode codes.
The name of the encoding file for the above convertion is iscii_unicode_dev. 

An example for conversion back to iscii would be :

	iconverter -e unicode_iscii_bng bng.uni bng.isc

   This does the conversion of an unicode coded bengali file to its equivalent iscii codes. 
unicode_iscii_bng is the encoding file used here.

Note : Only the name of the encoding file needs to be specified rather than the entire path 
viz. /usr/share/fonts/encodings/encoding_file_name. 

One can also specify one's own encoding_file in which case the entire path needs to be mentioned
with respect from the above mentioned directory.

Support is also provided for converting unicode coded files to their PostScript format.
The utility iscii2ps converts both iscii and unicode coded Indian language files to their 
PostScript format using the fonts that get installed with isciilib.

An example converting command is :

	iscii2ps dev.isc dev.isc.ps

	iscii2ps -unicode 2 bng.uni bng.uni.ps

   The first one does the conversion from iscii to PostScript while the second one converts the
input unicode file to PostScript.
   The unicode corresponding to a letter of an alphabet of a language comprises of two bytes. 
Hence the option "-unicode 2" has to be specified to iscii2ps for converting Unicode coded files
to their PostScript form.
   Here too the corresponding encoding file for conversions from iscii/unicode to PostScript for
each language exists in the same directory as above and gets installed along with the isciilib
package.
   The fonts provided by C-DAC (Centre for Development of advanced computing, India)
have been used for displaying Indian language scripts in PostScript format. These fonts also 
get installed along with isciilib and are used by the X-font server to generate the PS format.
The different fonts used for the different languages are listed below.

The following 10 Indian Languages are supported :

	Assamese
	Bengali
	Devanagari
	Gujarati
	Kannada
	Malayalam
	Oriya
	Punjabi
	Tamil
	Telugu


The code conversion files for the above languages are :
	
	For iscii_to_unicode : 			For unicode_to_iscii :
	  iscii_unicode_asm			  unicode_iscii_asm
	  iscii_unicode_bng			  unicode_iscii_bng
	  iscii_unicode_dev			  unicode_iscii_dev
	  iscii_unicode_gjr			  unicode_iscii_gjr
	  iscii_unicode_knd			  unicode_iscii_knd
	  iscii_unicode_mlm			  unicode_iscii_mlm
	  iscii_unicode_ori			  unicode_iscii_ori
	  iscii_unicode_pnj			  unicode_iscii_pnj
	  iscii_unicode_tml			  unicode_iscii_tml
	  iscii_unicode_tlg			  unicode_iscii_tlg

	For iscii-to-isfoc   :			For unicode-to-isfoc :
	  iscii_isfoc_asm			  unicode_isfoc_asm
	  iscii_isfoc_bng			  unicode_isfoc_bng
	  iscii_isfoc_dev			  unicode_isfoc_dev
	  iscii_isfoc_gjr			  unicode_isfoc_gjr
	  iscii_isfoc_knd			  unicode_isfoc_knd
	  iscii_isfoc_mlm			  unicode_isfoc_mlm
	  iscii_isfoc_ori			  unicode_isfoc_ori
	  iscii_isfoc_pnj			  unicode_isfoc_pnj
	  iscii_isfoc_tml			  unicode_isfoc_tml
	  iscii_isfoc_tlg			  unicode_isfoc_tlg


The fonts used for generating the PostScript format for the different languages are :

For Assamese   : -altsys-as_ttdurga-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Bengali    : -altsys-bn_ttdurga-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Devanagari : -altsys-dv_ttyogesh-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Gujarati   : -altsys-gj_ttanita-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Kannada    : -altsys-kn_ttpadmini-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Malayalam  : -altsys-ml_ttkarthika-medium-r-normal--0-0-0-0-p-0-ascii-0
For Oriya      : -altsys-or_ttsarala-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Punjabi    : -altsys-pn_ttamar-medium-r-normal--0-0-0-0-p-0-ascii-0
For Tamil      : -altsys-tm_ttvalluvar-medium-r-normal--0-0-0-0-p-0-iso8859-1
For Telugu     : -altsys-tl_ttharshapriya-medium-r-normal--0-0-0-0-p-0-iso8859-1

See Also : The man page for iconverter.