Tcl Built-In Commands                                encoding(1T)





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, depend-
     ing 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 speci-
          fied, 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 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 ASCI characters as singe bytes and  Japanese
     characters  as  two  bytes.   This  makes  it  easy to embed
     literal strings that correspond to non-ASCI  characters  by



Tcl                     Last change: 8.1                        1






Tcl Built-In Commands                                encoding(1T)



     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  encod-
     ing  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 Hira-
     gana letter HA.


SEE ALSO
     TclGetEncoding(3TCL)


KEYWORDS
     encoding

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     
       ATRIBUTE TYPE     ATRIBUTE VALUE
    
     Availability         SUNWTcl        
    
     Interface Stability  Uncommitted    
    

NOTES
     Source for Tcl is available on http:/opensolaris.org.















Tcl                     Last change: 8.1                        2