Officially
the FTP protocol (RFC959) only supports 7-bit ASCII characters. This
means that file and directory names transferred across the control channel can only be
ASCII.
However,
most FTP servers do support extended (i.e. 8-bit) ASCII. Unfortunately there are many types of extended ASCII and there is no
standard
for what extended ASCII encoding is to be used. As a result, the
meaning of characters 0 to
127 is well-defined, but the meaning of characters 128 to 255 varies
from one server to the
other. For example, one server might interpret character 193 as an accented A,
whereas another might
interpret it as an accented E.
By
default, 7-bit ASCII is supported. If a
character is encountered whose code is 128 to 255 it will be
represented as a question mark. The
setControlEncoding()
method on the advanced settings object allows the developer to select an 8-bit
character encoding that matches that of the server. Unfortunately many servers do not state
what 8-bit ASCII character set they are using, so it is often necessary to use trial and
error to find out. Some common character encodings to try for western European languages are windows-1252
and ISO-8859-1.
For
example, to set the command encoding to windows-1252:
