Ubuntu Manpage: uconv - convert data from one encoding to another

Provided by: icu-devtools_66.1-2ubuntu2.1_amd64

NAME

       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 provides 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 occurrence of such characters in
the input. Other callbacks 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 happen 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 transliteration 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 destination encoding.

--to-callback callback
Use callback to handle characters that cannot be transcoded to the destination encoding. See
section CALLBACKS 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 CALLBACKS 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 callbacks.

--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 anyway.

--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
transcoding: 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, along with a description of their behavior. The list of
callbacks actually supported by uconv is displayed when it is called with -h, --help.

substitute Write 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
hexadecimal value of the Unicode codepoint.

escape-xml-dec Replace the missing characters with a string of the format &#nnnn;, 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
hexadecimal 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 literature, delimited by curly braces for easy recognition of
those substitutions in the output.

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 occurring at the first invalid byte encountered. This may be confusing to
       users of GNU iconv(1), which reports errors as occurring 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 occurred.

AUTHORS

       Jonas Utterstroem
       Yves Arrouye

VERSION

       66.1

COPYRIGHT

       Copyright (C) 2000-2005 IBM, Inc. and others.