encoding(n) Tcl Built-In Commands encoding(n)______________________________________________________________________________NAMEencoding - Manipulate encodings
SYNOPSISencoding option ?arg arg ...?
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.
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 char‐
acters 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 encod‐
ing. If encoding is not specified, the current system encoding
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 specified, the current system
encoding is used.
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.
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. How‐
ever, 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
SEE ALSOTcl_GetEncoding(3)KEYWORDSencodingTcl 8.1 encoding(n)