Home : Computers : Linux : Man Pages : preconv

preconv



SYNOPSIS

       preconv [-dr] [-e encoding] [files ...]
       preconv -h | --help
       preconv -v | --version

       It is possible to have whitespace between the -e  command  line  option
       and its parameter.


DESCRIPTION

       preconv reads files and converts its encoding(s) to a form GNU troff(1)
       can process, sending the data  to  standard  output.   Currently,  this
       means ASCII characters and `\[uXXXX]' entities, where `XXXX' is a hexa-
       decimal number with four to six digits, representing  a  Unicode  input
       code.   Normally,  preconv should be invoked with the -k and -K options
       of groff.


OPTIONS

       -d     Emit debugging messages  to  standard  error  (mainly  the  used
              encoding).

       -Dencoding
              Specify default encoding if everything fails (see below).

       -eencoding
              Specify input encoding explicitly, overriding all other methods.
              This corresponds to groff's  -Kencoding  option.   Without  this
              switch, preconv uses the algorithm described below to select the
              input encoding.

       --help
       -h     Print help message.

       -r     Do not add .lf requests.

       --version
       -v     Print version number.


USAGE

       preconv tries to find the input encoding with the following algorithm.

       1.     If the input encoding has been explicitly specified with  option
              -e, use it.

       2.     Otherwise, check whether the input starts with a Byte Order Mark
              (BOM, see below).  If found, use it.

       3.     Finally, check whether there is a known coding tag  (see  below)
              in either the first or second input line.  If found, use it.

       4.     If everything fails, use a default encoding as given with option
              -D, by the current locale, or `latin1' if the locale is  set  to

       protocol; in other words, preconv's output doesn't contain it.

       Note that U+FEFF not at the start of the input data actually  is  emit-
       ted; it has then the meaning of a `zero width no-break space' character
       - something not needed normally in groff.

   Coding Tags
       Editors which support more than a single character encoding  need  tags
       within the input files to mark the file's encoding.  While it is possi-
       ble to guess the right input encoding with the help of heuristic  algo-
       rithms  for  data  which  represents a greater amount of a natural lan-
       guage, it is still just a guess.   Additionally,  all  algorithms  fail
       easily for input which is either too short or doesn't represent a natu-
       ral language.

       For these reasons, preconv supports the  coding  tag  convention  (with
       some  restrictions) as used by GNU Emacs and XEmacs (and probably other
       programs too).

       Coding tags in GNU Emacs and XEmacs are stored in so-called File  Vari-
       ables.   preconv recognizes the following syntax form which must be put
       into a troff comment in the first or second line.

              -*- tag1: value1; tag2: value2; ... -*-

       The only relevant tag for preconv is `coding' which can take the values
       listed below.  Here an example line which tells Emacs to edit a file in
       troff mode, and to use latin2 as its encoding.

              .\" -*- mode: troff; coding: latin-2 -*-

       The following list gives all MIME  coding  tags  (either  lowercase  or
       uppercase) supported by preconv; this list is hard-coded in the source.

              big5, cp1047, euc-jp, euc-kr, gb2312, iso-8859-1, iso-8859-2,
              iso-8859-5, iso-8859-7, iso-8859-9, iso-8859-13, iso-8859-15,
              koi8-r, us-ascii, utf-8, utf-16, utf-16be, utf-16le

       In  addition, the following hard-coded list of other tags is recognized
       which eventually map to values from the list above.

              ascii, chinese-big5, chinese-euc, chinese-iso-8bit, cn-big5,
              cn-gb, cn-gb-2312, cp878, csascii, csisolatin1,
              cyrillic-iso-8bit, cyrillic-koi8, euc-china, euc-cn, euc-japan,
              euc-japan-1990, euc-korea, greek-iso-8bit, iso-10646/utf8,
              iso-10646/utf-8, iso-latin-1, iso-latin-2, iso-latin-5,
              iso-latin-7, iso-latin-9, japanese-euc, japanese-iso-8bit, jis8,
              koi8, korean-euc, korean-iso-8bit, latin-0, latin1, latin-1,
              latin-2, latin-5, latin-7, latin-9, mule-utf-8, mule-utf-16,
              mule-utf-16be, mule-utf-16-be, mule-utf-16be-with-signature,
              mule-utf-16le, mule-utf-16-le, mule-utf-16le-with-signature,
              utf8, utf-16-be, utf-16-be-with-signature,


BUGS

       preconv doesn't support local variable lists yet.  This is a  different
       syntax form to specify local variables at the end of a file.


SEE ALSO

       groff(1)
       the GNU Emacs and XEmacs info pages


Groff Version 1.22.2 7 February 2013 PRECONV(1)



Subscribe to us on YouTube