Oops; let's leave off `-v' from the tar command line, or my nightly

[sgt/utils] / cvt-utf8 / cvt-utf8.but

\cfg{man-identity}{cvt-utf8}{1}{2004-03-24}{Simon Tatham}{Simon Tatham}
\cfg{html-chapter-numeric}{yes}

\title Man page for \cw{cvt-utf8}

\U NAME

\cw{cvt-utf8} - convert between UTF-8 and Unicode, and analyse Unicode

\U SYNOPSIS

\c cvt-utf8 [flags] [hex UTF-8 bytes and/or U+codepoints]
\e bbbbbbbb  iiiii   iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

\U DESCRIPTION

\cw{cvt-utf8} is a tool for manipulating and analysing UTF-8 and
Unicode data. Its functions include:

\b Given a sequence of Unicode code points, convert them to the
corresponding sequence of bytes in the UTF-8 encoding.

\b Given a sequence of UTF-8 bytes, convert them back into Unicode
code points.

\b Given any combination of the above inputs, look up each Unicode
code point in the Unicode character database and identify it.

\b Look up Unified Han characters in the \q{Unihan} database and
provide their translation text.

By default, \cw{cvt-utf8} expects to receive hex numbers (either
UTF-8 bytes or Unicode code points) on the command line, and it will
print out a verbose analysis of the input data. If you need it to
read UTF-8 from standard input or to write pure UTF-8 to standard
output, you can do so using command-line options.

\U OPTIONS

\dt \cw{-i}

\dd Read UTF-8 data from standard input and analyse that, instead of
expecting hex numbers on the command line.

\dt \cw{-o}

\dd Write well-formed UTF-8 to standard output, instead of writing a
long analysis of the input data.

\dt \cw{-h}

\dd Look up each code point in the Unihan database as well as the
main Unicode character database.

\U EXAMPLES

In \cw{cvt-utf8}'s native mode, it simply analyses input Unicode or
UTF-8 data. For example, you can give a list of Unicode code
points...

\c $ cvt-utf8 U+20ac U+31 U+30
\e   bbbbbbbbbbbbbbbbbbbbbbbbb
\c U-000020AC  E2 82 AC          EURO SIGN
\c U-00000031  31                DIGIT ONE
\c U-00000030  30                DIGIT ZERO

... and \cw{cvt-utf8} gives you the UTF-8 encodings plus the
character definitions.

Alternatively, you can supply a list of UTF-8 bytes...

\c $ cvt-utf8 D0 A0 D1 83 D1 81 D1 81 D0 BA D0 B8 D0 B9
\e   bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
\c U-00000420  D0 A0             CYRILLIC CAPITAL LETTER ER
\c U-00000443  D1 83             CYRILLIC SMALL LETTER U
\c U-00000441  D1 81             CYRILLIC SMALL LETTER ES
\c U-00000441  D1 81             CYRILLIC SMALL LETTER ES
\c U-0000043A  D0 BA             CYRILLIC SMALL LETTER KA
\c U-00000438  D0 B8             CYRILLIC SMALL LETTER I
\c U-00000439  D0 B9             CYRILLIC SMALL LETTER SHORT I

... and you get back the same output format, including the UTF-8
code points.

If you supply malformed data, \cw{cvt-utf8} will break it down for
you and identify the malformed pieces and any correctly formed
characters:

\c $ cvt-utf8 A9 FE 45 C2 80 90 0A
\e   bbbbbbbbbbbbbbbbbbbbbbbbbbbbb
\c             A9                (unexpected continuation byte)
\c             FE                (invalid UTF-8 byte)
\c U-00000045  45                LATIN CAPITAL LETTER E
\c U-00000080  C2 80             <control>
\c             90                (unexpected continuation byte)
\c U-0000000A  0A                <control>

If you need the UTF-8 encoding of a particular character, you can
use the \cw{-o} option to cause the UTF-8 to be written to standard
output:

\c $ cvt-utf8 -o U+20AC >> my-utf8-file.txt
\e   bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb

If you have UTF-8 data in a file or output from another program, you
can use the \cw{-i} option to have \cw{cvt-utf8} analyse it. This
works particularly well if you also have my \cw{xcopy} program,
which can be told to extract UTF-8 data from the X selection and
write it to its standard output. With these two programs working
together, if you ever have trouble identifying some text in a
UTF-8-supporting web browser such as Mozilla, you can simply select
the text in question, switch to a terminal window, and type

\c $ xcopy -u -r | cvt-utf8 -i
\e   bbbbbbbbbbbbbbbbbbbbbbbbb

If the text is in Chinese, you can get at least a general idea of
its meaning by using the \cw{-h} option to print the meaning of each
ideograph from the Unihan database. For example, if you pass in the
Chinese text meaning \q{Traditional Chinese}:

\c $ cvt-utf8 -h U+7E41 U+9AD4 U+4E2D U+6587
\e   bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
\c U-00007E41  E7 B9 81          <han> complicated, complex, difficult
\c U-00009AD4  E9 AB 94          <han> body; group, class, body, unit
\c U-00004E2D  E4 B8 AD          <han> central; center, middle; in the
\c                               midst of; hit (target); attain
\c U-00006587  E6 96 87          <han> literature, culture, writing

\U ADMINISTRATION

In order to print the \cw{unicode.org} official name of each
character, \cw{cvt-utf8} requires file mapping code points to names.
This file is in DBM database format, for rapid lookup.

This database file is accessed using the Python \cw{anydbm} module,
so its precise file name will vary depending on what flavours of DBM
you have installed. The name Python knows it by is \cq{unicode}; it
may actually be called \cq{unicode.db} or something similar.

\cw{cvt-utf8} generates this DBM file itself starting from the
Unicode Character Database, in the form of the file
\cw{UnicodeData.txt} supplied by \cw{unicode.org}. It supports two
administrative options for this purpose:

\c cvt-utf8 --build /path/to/UnicodeData.txt /path/to/unicode

Given a copy of \cw{UnicodeData.txt} on disk, this mode will create
the DBM file and store it in a place of your choice.

\c cvt-utf8 --fetch-build /path/to/unicode

If you have a direct Internet connection, this will automatically
download the text file from \cw{unicode.org} and process it straight
into the DBM file.

There is a second DBM file, known to Python as \cw{unihan}, which is
required to support the \cw{-h} option. This one is built from the
Unihan Database, distributed by \cw{unicode.org} as a zip file
containing a text file \cw{Unihan.txt}.

If you already have \cw{Unihan.txt} on your system, you can build
\cw{cvt-utf8}'s \cw{unihan} DBM file like this:

\c cvt-utf8 --build-unihan /path/to/Unihan.txt /path/to/unihan

Or, again, \cw{cvt-utf8} can automatically download it from
\cw{unicode.org}, unpack the zip file on the fly, and write the DBM
straight out:

\c cvt-utf8 --fetch-build-unihan /path/to/unihan

\cw{cvt-utf8} expects to find these database files in one of the
following locations:

\c /usr/share/unicode
\c /usr/lib/unicode
\c /usr/local/share/unicode
\c /usr/local/lib/unicode
\c $HOME/share/unicode
\e iiiii
\c $HOME/lib/unicode
\e iiiii

If either of these files is not found, \cw{cvt-utf8} will still
perform the rest of its functions.

\U LICENCE

\cw{cvt-utf8} is free software, distributed under the MIT licence.
Type \cw{cvt-utf8 --licence} to see the full licence text.