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  3. tcl
  4. encoding(n)

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





NAME


encoding - Manipulate encodings






SYNOPSIS


encoding option ?arg arg ...?










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:



  

  
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.

  

  
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.

  

  
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.

  

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

  

  
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


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







  

    8.1
    Tcl