From Linux Man Pages
uconv - convert data from one encoding to another
SYNOPSIS
uconv [ -h, -?, --help ] [ -V, --version ] [ -s, --silent ] [ -v, --verbose ] [ -l, --list | -l, --list-code code
| --default-code | -L, --list-transliterators ] [ --canon ] [ -x transliteration ] [ --to-callback callback | -c
] [ --from-callback callback | -i ] [ --callback callback ] [ --fallback | --no-fallback ] [ -b, --block-size
size ] [ -f, --from-code encoding ] [ -t, --to-code encoding ] [ --add-signature ] [ --remove-signature ] [ -o,
--output file ] [ file... ]
DESCRIPTION
uconv converts, or transcodes, each given file (or its standard input if no file is specified) from one encoding
to another. The transcoding is done using Unicode as a pivot encoding (i.e. the data are first transcoded from
their original encoding to Unicode, and then from Unicode to the destination encoding).
If an encoding is not specified or is -, the default encoding is used. Thus, calling uconv with no encoding pro-
vides an easy way to validate and sanitize data files for further consumption by tools requiring data in the
default encoding.
When calling uconv, it is possible to specify callbacks that are used to handle invalid characters in the input,
or characters that cannot be transcoded to the destination encoding. Some encodings, for example, offer a default
substitution character that can be used to represent the occurence of such characters in the input. Other call-
backs offer a useful visual representation of the invalid data.
uconv can also run the specified transliteration on the transcoded data, in which case transliteration will hap-
pen as an intermediate step, after the data have been transcoded to Unicode. The transliteration can be either a
list of semicolon-separated transliterator names, or an arbitrarily complex set of rules in the ICU translitera-
tion rules format.
For transcoding purposes, uconv options are compatible with those of iconv(1), making it easy to replace it in
scripts. It is not necessarily the case, however, that the encoding names used by uconv and ICU are the same as
the ones used by iconv(1). Also, options that provide informational data, such as the -l, --list one offered by
some iconv(1) variants such as GNU's, produce data in a slightly different and easier to parse format.
OPTIONS
-h, -?, --help
Print help about usage and exit.
-V, --version
Print the version of uconv and exit.
-s, --silent
Suppress messages during execution.
-v, --verbose
Display extra informative messages during execution.
-l, --list
List all the available encodings and exit.
-l, --list-code code
List only the code encoding and exit. If code is not a proper encoding, exit with an error.
--default-code
List only the name of the default encoding and exit.
-L, --list-transliterators
List all the available transliterators and exit.
--canon
If used with -l, --list or --default-code, the list of encodings is produced in a format compatible with
convrtrs.txt(5). If used with -L, --list-transliterators, print only one transliterator name per line.
-x transliteration
Run the given transliteration on the transcoded Unicode data, and use the transliterated data as input for
the transcoding to the the destination encoding.
--to-callback callback
Use callback to handle characters that cannot be transcoded to the destination encoding. See section CALL-
BACKS for details on valid callbacks.
-c Omit invalid characters from the output. Same as --to-callback skip.
--from-callback callback
Use callback to handle characters that cannot be transcoded from the original encoding. See section CALL-
BACKS for details on valid callbacks.
-i Ignore invalid sequences in the input. Same as --from-callback skip.
--callback callback
Use callback to handle both characters that cannot be transcoded from the original encoding and characters
that cannot be transcoded to the destination encoding. See section CALLBACKS for details on valid call-
backs.
--fallback
Use the fallback mapping when transcoding from Unicode to the destination encoding.
--no-fallback
Do not use the fallback mapping when transcoding from Unicode to the destination encoding. This is the
default.
-b, --block-size size
Read input in blocks of size bytes at a time. The default block size is 4096.
-f, --from-code encoding
Set the original encoding of the data to encoding.
-t, --to-code encoding
Transcode the data to encoding.
--add-signature
Add a U+FEFF Unicode signature character (BOM) if the output charset supports it and does not add one any-
way.
--remove-signature
Remove a U+FEFF Unicode signature character (BOM).
-o, --output file
Write the transcoded data to file.
CALLBACKS
uconv supports specifying callbacks to handle invalid data. Callbacks can be set for both directions of transcod-
ing: from the original encoding to Unicode, with the --from-callback option, and from Unicode to the destination
encoding, with the --to-callback option.
The following is a list of valid callback names, alonmg with a description of their behavior. The list of call-
backs actually supported by uconv is displayed when it is called with -h, --help.
substitute Write the the encoding's substitute sequence, or the Unicode replacement character U+FFFD when
transcoding to Unicode.
skip Ignore the invalid data.
stop Stop with an error when encountering invalid data. This is the default callback.
escape Same as escape-icu.
escape-icu Replace the missing characters with a string of the format %Uhhhh for plane 0 characters, and
%Uhhhh%Uhhhh for planes 1 and above characters, where hhhh is the hexadecimal value of one of
the UTF-16 code units representing the character. Characters from planes 1 and above are written
as a pair of UTF-16 surrogate code units.
escape-java Replace the missing characters with a string of the format \uhhhh for plane 0 characters, and
\uhhhh\uhhhh for planes 1 and above characters, where hhhh is the hexadecimal value of one of
the UTF-16 code units representing the character. Characters from planes 1 and above are written
as a pair of UTF-16 surrogate code units.
escape-c Replace the missing characters with a string of the format \uhhhh for plane 0 characters, and
\Uhhhhhhhh for planes 1 and above characters, where hhhh and hhhhhhhh are the hexadecimal values
of the Unicode codepoint.
escape-xml Same as escape-xml-hex.
escape-xml-hex Replace the missing characters with a string of the format &#xhhhh;, where hhhh is the hexadeci-
mal value of the Unicode codepoint.
escape-xml-dec Replace the missing characters with a string of the format &#xnnnn;, where nnnn is the decimal
value of the Unicode codepoint.
escape-unicode Replace the missing characters with a string of the format {U+hhhh}, where hhhh is the hexadeci-
mal value of the Unicode codepoint. That hexadecimal string is of variable length and can use
from 4 to 6 digits. This is the format universally used to denote a Unicode codepoint in the
litterature, delimited by curly braces for easy recognition of those substitutions in the out-
put.
EXAMPLES
Convert data from a given encoding to the platform encoding:
$ uconv -f encoding
Check if a file contains valid data for a given encoding:
$ uconv -f encoding -c file >/dev/null
Convert a UTF-8 file to a given encoding and ensure that the resulting text is good for any version of HTML:
$ uconv -f utf-8 -t encoding \
--callback escape-xml-dec file
Display the names of the Unicode code points in a UTF-file:
$ uconv -f utf-8 -x any-name file
Print the name of a Unicode code point whose value is known (U+30AB in this example):
$ echo '\u30ab' | uconv -x 'hex-any; any-name'; echo
{KATAKANA LETTER KA}{LINE FEED}
$
(The names are delimited by curly braces. Also, the name of the line terminator is also displayed.)
Normalize UTF-8 data using Unicode NFKC, remove all control characters, and map Katakana to Hiragana:
$ uconv -f utf-8 -t utf-8 \
-x '::nfkc; [:Cc:] >; ::katakana-hiragana;'
CAVEATS AND BUGS
uconv does report errors as occuring at the first invalid byte encountered. This may be confusing to users of GNU
iconv(1), which reports errors as occuring at the first byte of an invalid sequence. For multi-byte character
sets or encodings, this means that uconv error positions may be at a later offset in the input stream than would
be the case with GNU iconv(1).
The reporting of error positions when a transliterator is used may be inaccurate or unavailable, in which case
uconv will report the offset in the output stream at which the error occured.
VERSION
3.4
COPYRIGHT
Copyright (C) 2000-2005 IBM, Inc. and others.
RELATED
iconv(1)
CATEGORY