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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 logically a sequence of 16-bit Unicode characters.
       These strings are represented in memory as a sequence of bytes that may
       be in one of several encodings: modified UTF-8 (which uses 1 to 3 bytes
       per character), 16-bit "Unicode" (which uses 2 bytes per character,
       with an endianness that is dependent on the host architecture), and
       binary (which uses a single byte per character but only handles a
       restricted range of characters).  Tcl does not guarantee to always use
       the same encoding for the same string.

       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 (indeed, the resulting string is a binary string as
              far as Tcl is concerned, at least initially).  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 directory, that element is ignored.

       encoding names
              Returns a list containing the names of all of the encodings that
              are currently available.  The encodings "utf-8" and "iso8859-1"
              are guaranteed to be present in the list.

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


EXAMPLE

       The following example converts a byte sequence in Japanese euc-jp
       encoding to a TCL string:

              set s [encoding convertfrom euc-jp "\xA4\xCF"]

       The result is the unicode codepoint: "\u306F", which is the Hiragana
       letter HA.


SEE ALSO

       Tcl_GetEncoding(3)


KEYWORDS

       encoding, unicode

Tcl                                   8.1                          encoding(n)

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