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encoding(n)                                 Tcl Built-In Commands                                encoding(n)



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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 speci-fied, specified,
              fied, 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 charac-ter. character.
              ter.  If encoding is not specified, the current system encoding is used.

       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  cur-rent current
              rent  system  encoding.   The  system  encoding  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 "\xA4\xCF"]
       would return the Unicode string "\u306F", which is the Hiragana letter HA.


SEE ALSO
       Tcl_GetEncoding(3)


KEYWORDS
       encoding



Tcl                                                  8.1                                         encoding(n)