Scroll to navigation

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





NAME


encoding - Manipulate encodings






SYNOPSIS


encoding option ?arg arg ...?








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:



  

  
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 (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.

  

  
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. The encodings “utf-8” and
      “iso8859-1” are guaranteed to be present in the list.

  

  
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(3tcl), fconfigure(3tcl)






KEYWORDS


encoding, unicode







  

    8.1
    Tcl