encoding(3tcl)						       Tcl Built-In Commands						    encoding(3tcl)

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NAME

       encoding - Manipulate encodings

SYNOPSIS

       encoding option ?arg arg ...?
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INTRODUCTION

       Strings	in Tcl are encoded using 16-bit Unicode characters.  Different operating system interfaces or applications may generate strings in
       other encodings such as Shift-JIS.  The encoding command helps to bridge the gap between Unicode and these other formats.

DESCRIPTION

       Performs one of several encoding related operations, depending on option.  The legal options are:

       encoding convertfrom ?encoding? data
	      Convert data to Unicode from the specified encoding.  The characters in data are treated as binary data where the  lower	8-bits	of
	      each  character  is  taken  as a single byte.  The resulting sequence of bytes is treated as a string in the specified encoding.	If
	      encoding is not specified, the current system encoding is used.

       encoding convertto ?encoding? string
	      Convert string from Unicode to the specified encoding.  The result is a sequence of bytes  that  represents  the	converted  string.
	      Each byte is stored in the lower 8-bits of a Unicode character.  If encoding is not specified, the current system encoding is used.

       encoding dirs ?directoryList?
	      Tcl  can load encoding data files from the file system that describe additional encodings for it to work with. This command sets the |
	      search path for *.enc encoding data files to the list of directories directoryList. If directoryList is  omitted	then  the  command |
	      returns  the  current list of directories that make up the search path. It is an error for directoryList to not be a valid list. If, |
	      when a search for an encoding data file is happening, an element in directoryList does not refer to a  readable,	searchable  direc- |
	      tory, that element is ignored.

       encoding names
	      Returns a list containing the names of all of the encodings that are currently available.

       encoding system ?encoding?
	      Set the system encoding to encoding. If encoding is omitted then the command returns the current system encoding.  The system encod-
	      ing is used whenever Tcl passes strings to system calls.

EXAMPLE

       It is common practice to write script files using a text editor that produces output in the euc-jp encoding,  which  represents	the  ASCII
       characters  as  singe bytes and Japanese characters as two bytes.  This makes it easy to embed literal strings that correspond to non-ASCII
       characters by simply typing the strings in place in the script.	However, because the source command always reads files using  the  current
       system encoding, Tcl will only source such files correctly when the encoding used to write the file is the same.  This tends not to be true
       in an internationalized setting.  For example, if such a file was sourced in North America (where the ISO8859-1	is  normally  used),  each
       byte  in the file would be treated as a separate character that maps to the 00 page in Unicode.	The resulting Tcl strings will not contain
       the expected Japanese characters.  Instead, they will contain a sequence of Latin-1 characters that correspond to the bytes of the original
       string.	The encoding command can be used to convert this string to the expected Japanese Unicode characters.  For example,
	      set s [encoding convertfrom euc-jp "xA4xCF"]
       would return the Unicode string "u306F", which is the Hiragana letter HA.

SEE ALSO

       Tcl_GetEncoding(3tcl)

KEYWORDS

       encoding

Tcl									8.1							    encoding(3tcl)