nkf(1) nkf(1)
NAME
nkf - Network Kanji Filter
SYNOPSIS
nkf [-butjnesliohrTVvwWJESZxXFfmMBOcdILg] [file ...]
DESCRIPTION
Nkf is a yet another kanji code converter among networks, hosts and
terminals. It converts input kanji code to designated kanji code such
as ISO-2022-JP, Shift_JIS, EUC-JP, UTF-8, UTF-16 or UTF-32.
One of the most unique faculty of nkf is the guess of the input kanji
encodings. It currently recognizes ISO-2022-JP, Shift_JIS, EUC-JP,
UTF-8, UTF-16 and UTF-32. So users needn't set the input kanji code
explicitly.
By default, X0201 kana is converted into X0208 kana. For X0201 kana,
SO/SI, SSO and ESC-(-I methods are supported. For automatic code
detection, nkf assumes no X0201 kana in Shift_JIS. To accept X0201 in
Shift_JIS, use -X, -x or -S.
multiple options are specified as seprate strings, such as
print nkf('--ic=UTF8-MAC', '-w', $string), "\n";
except the last arguments.
OPTIONS
-J -S -E -W -W16 -W32 -j -s -e -w -w16 -w32
Specify input and output encodings. Upper case is input. cf. --ic
and --oc.
-J ISO-2022-JP (JIS code).
-S Shift_JIS and JIS X 0201 kana. EUC-JP is recognized as X0201
kana. Without -x flag, JIS X 0201 Katakana (a.k.a.halfwidth
kana) is converted into JIS X 0208. If you use Windows, see
Windows-31J (CP932).
-E EUC-JP.
-W UTF-8N.
-W16[BL][0]
UTF-16. B or L gives whether Big Endian or Little Endian. 0
gives whther put BOM or not.
-W32[BL][0]
UTF-32. B or L gives whether Big Endian or Little Endian. 0
gives whther put BOM or not.
-b -u
Output is buffered (DEFAULT), Output is unbuffered.
-t No conversion.
-i[@B]
Specify the escape sequence for JIS X 0208.
-i@ Use ESC ( @. (JIS X 0208-1978)
-iB Use ESC ( B. (JIS X 0208-1983/1990 DEFAULT)
-o[BJ]
Specify the escape sequence for US-ASCII/JIS X 0201 Roman. (DEFAULT
B)
-r {de/en}crypt ROT13/47
-h[123] --hiragana --katakana --katakana-hiragana
-h1 --hiragana
Katakana to Hiragana conversion.
-h2 --katakana
Hiragana to Katakana conversion.
-h3 --katakana-hiragana
Katakana to Hiragana and Hiragana to Katakana conversion.
-T Text mode output (MS-DOS)
-f[m [- n]]
Folding on m length with n margin in a line. Without this option,
fold length is 60 and fold margin is 10.
-F New line preserving line folding.
-Z[0-3]
Convert X0208 alphabet (Fullwidth Alphabets) to ASCII.
-Z -Z0
Convert X0208 alphabet to ASCII.
-Z1 Convert X0208 kankaku to single ASCII space.
-Z2 Convert X0208 kankaku to double ASCII spaces.
-Z3 Replacing fullwidth >, <, ", & into '>', '<', '"',
'&' as in HTML.
-X -x
With -X or without this option, X0201 is converted into X0208 Kana.
With -x, try to preserve X0208 kana and do not convert X0201 kana to
X0208. In JIS output, ESC-(-I is used. In EUC output, SS2 is used.
-B[0-2]
Assume broken JIS-Kanji input, which lost ESC. Useful when your
site is using old B-News Nihongo patch.
-B1 allows any chars after ESC-( or ESC-$.
-B2 force ASCII after NL.
-I Replacing non iso-2022-jp char into a geta character (substitute
character in Japanese).
-m[BQN0]
MIME ISO-2022-JP/ISO8859-1 decode. (DEFAULT) To see ISO8859-1
(Latin-1) -l is necessary.
-mB Decode MIME base64 encoded stream. Remove header or other part
before conversion.
-mQ Decode MIME quoted stream. '_' in quoted stream is converted to
space.
-mN Non-strict decoding. It allows line break in the middle of the
base64 encoding.
-m0 No MIME decode.
-M MIME encode. Header style. All ASCII code and control characters are
intact.
-MB MIME encode Base64 stream. Kanji conversion is performed before
encoding, so this cannot be used as a picture encoder.
-MQ Perform quoted encoding.
-l Input and output code is ISO8859-1 (Latin-1) and ISO-2022-JP. -s,
-e and -x are not compatible with this option.
-L[uwm] -d -c
Convert line breaks.
-Lu -d
unix (LF)
-Lw -c
windows (CRLF)
-Lm mac (CR)
Without this option, nkf doesn't convert line breaks.
--fj --unix --mac --msdos --windows
Convert for these systems.
--jis --euc --sjis --mime --base64
Convert to named code.
--jis-input --euc-input --sjis-input --mime-input --base64-input
Assume input system
--ic=input codeset --oc=output codeset
Set the input or output codeset. NKF supports following codesets
and those codeset names are case insensitive.
ISO-2022-JP
a.k.a. RFC1468, 7bit JIS, JUNET
EUC-JP (eucJP-nkf)
a.k.a. AT&T JIS, Japanese EUC, UJIS
eucJP-ascii
eucJP-ms
CP51932
Microsoft Version of EUC-JP.
Shift_JIS
a.k.a. SJIS, MS_Kanji
Windows-31J
a.k.a. CP932
UTF-8
same as UTF-8N
UTF-8N
UTF-8 without BOM
UTF-8-BOM
UTF-8 with BOM
UTF8-MAC (input only)
decomposed UTF-8
UTF-16
same as UTF-16BE
UTF-16BE
UTF-16 Big Endian without BOM
UTF-16BE-BOM
UTF-16 Big Endian with BOM
UTF-16LE
UTF-16 Little Endian without BOM
UTF-16LE-BOM
UTF-16 Little Endian with BOM
UTF-32
same as UTF-32BE
UTF-32BE
UTF-32 Big Endian without BOM
UTF-32BE-BOM
UTF-32 Big Endian with BOM
UTF-32LE
UTF-32 Little Endian without BOM
UTF-32LE-BOM
UTF-32 Little Endian with BOM
--fb-{skip, html, xml, perl, java, subchar}
Specify the way that nkf handles unassigned characters. Without
this option, --fb-skip is assumed.
--prefix=escape charactertarget character..
When nkf converts to Shift_JIS, nkf adds a specified escape
character to specified 2nd byte of Shift_JIS characters. 1st byte
of argument is the escape character and following bytes are target
characters.
--no-cp932ext
Handle the characters extended in CP932 as unassigned characters.
--no-best-fit-chars
When Unicode to Encoded byte conversion, don't convert characters
which is not round trip safe. When Unicode to Unicode conversion,
with this and -x option, nkf can be used as UTF converter. (In
other words, without this and -x option, nkf doesn't save some
characters)
When nkf converts strings that related to path, you should use this
option.
--cap-input
Decode hex encoded characters.
--url-input
Unescape percent escaped characters.
--numchar-input
Decode character reference, such as "&#....;".
--in-place[=SUFFIX] --overwrite[=SUFFIX]
Overwrite original listed files by filtered result.
Note --overwrite preserves timestamps of original files.
--guess=[12]
Print guessed encoding and newline. (2 is default, 1 is only
encoding)
--help
Print nkf's help.
--version
Print nkf's version.
-- Ignore rest of -option.
AUTHOR
Copyright (c) 1987, Fujitsu LTD. (Itaru ICHIKAWA).
Copyright (c) 1996-2018, The nkf Project.
nkf 2.1.5 2018-12-15 nkf(1)
Generated by dwww version 1.16 on Sat Oct 3 07:34:43 CEST 2026.