NAME
dos2unix - DOS/Mac to Unix and vice versa text file format converter
SYNOPSIS
dos2unix [options] [FILE ...] [-n INFILE OUTFILE ...]
unix2dos [options] [FILE ...] [-n INFILE OUTFILE ...]
DESCRIPTION
The Dos2unix package includes utilities "dos2unix" and "unix2dos" to
convert plain text files in DOS or Mac format to Unix format and vice
versa.
In DOS/Windows text files a line break, also known as newline, is a
combination of two characters: a Carriage Return (CR) followed by a Line
Feed (LF). In Unix text files a line break is a single character: the
Line Feed (LF). In Mac text files, prior to Mac OS X, a line break was
single Carriage Return (CR) character. Nowadays Mac OS uses Unix style
(LF) line breaks.
Besides line breaks Dos2unix can also convert the encoding of files. A
few DOS code pages can be converted to Unix Latin-1. And Windows Unicode
(UTF-16) files can be converted to Unix Unicode (UTF-8) files.
Binary files are automatically skipped, unless conversion is forced.
Non-regular files, such as directories and FIFOs, are automatically
skipped.
Symbolic links and their targets are by default kept untouched. Symbolic
links can optionally be replaced, or the output can be written to the
symbolic link target. Writing to a symbolic link target is not supported
on Windows.
Dos2unix was modelled after dos2unix under SunOS/Solaris. There is one
important difference with the original SunOS/Solaris version. This
version does by default in-place conversion (old file mode), while the
original SunOS/Solaris version only supports paired conversion (new file
mode). See also options "-o" and "-n". Another difference is that the
SunOS/Solaris version uses by default *iso* mode conversion while this
version uses by default *ascii* mode conversion.
OPTIONS
-- Treat all following options as file names. Use this option if you
want to convert files whose names start with a dash. For instance to
convert a file named "-foo", you can use this command:
dos2unix -- -foo
Or in new file mode:
dos2unix -n -- -foo out.txt
--allow-chown
Allow file ownership change in old file mode.
When this option is used, the conversion will not be aborted when
the user and/or group ownership of the original file can't be
preserved in old file mode. Conversion will continue and the
converted file will get the same new ownership as if it was
converted in new file mode. See also options "-o" and "-n". This
option is only available if dos2unix has support for preserving the
user and group ownership of files.
-ascii
Convert only line breaks. This is the default conversion mode.
-iso
Conversion between DOS and ISO-8859-1 character set. See also
section CONVERSION MODES.
-1252
Use Windows code page 1252 (Western European).
-437
Use DOS code page 437 (US). This is the default code page used for
ISO conversion.
-850
Use DOS code page 850 (Western European).
-860
Use DOS code page 860 (Portuguese).
-863
Use DOS code page 863 (French Canadian).
-865
Use DOS code page 865 (Nordic).
-7 Convert 8 bit characters to 7 bit space.
-b, --keep-bom
Keep Byte Order Mark (BOM). When the input file has a BOM, write a
BOM in the output file. This is the default behavior when converting
to DOS line breaks. See also option "-r".
-c, --convmode CONVMODE
Set conversion mode. Where CONVMODE is one of: *ascii*, *7bit*,
*iso*, *mac* with ascii being the default.
-D, --display-enc ENCODING
Set encoding of displayed text. Where ENCODING is one of: *ansi*,
*unicode*, *unicodebom*, *utf8*, *utf8bom* with ansi being the
default.
This option is only available in dos2unix for Windows with Unicode
file name support. This option has no effect on the actual file
names read and written, only on how they are displayed.
There are several methods for displaying text in a Windows console
based on the encoding of the text. They all have their own
advantages and disadvantages.
ansi
Dos2unix's default method is to use ANSI encoded text. The
advantage is that it is backwards compatible. It works with
raster and TrueType fonts. In some regions you may need to
change the active DOS OEM code page to the Windows system ANSI
code page using the "chcp" command, because dos2unix uses the
Windows system code page.
The disadvantage of ansi is that international file names with
characters not inside the system default code page are not
displayed properly. You will see a question mark, or a wrong
symbol instead. When you don't work with foreign file names this
method is OK.
unicode, unicodebom
The advantage of unicode (the Windows name for UTF-16) encoding
is that text is usually properly displayed. There is no need to
change the active code page. You may need to set the console's
font to a TrueType font to have international characters
displayed properly. When a character is not included in the
TrueType font you usually see a small square, sometimes with a
question mark in it.
When you use the ConEmu console all text is displayed properly,
because ConEmu automatically selects a good font.
The disadvantage of unicode is that it is not compatible with
ASCII. The output is not easy to handle when you redirect it to
another program.
When method "unicodebom" is used the Unicode text will be
preceded with a BOM (Byte Order Mark). A BOM is required for
correct redirection or piping in PowerShell.
utf8, utf8bom
The advantage of utf8 is that it is compatible with ASCII. You
need to set the console's font to a TrueType font. With a
TrueType font the text is displayed similar as with the
"unicode" encoding.
The disadvantage is that when you use the default raster font
all non-ASCII characters are displayed wrong. Not only unicode
file names, but also translated messages become unreadable. On
Windows configured for an East-Asian region you may see a lot of
flickering of the console when the messages are displayed.
In a ConEmu console the utf8 encoding method works well.
When method "utf8bom" is used the UTF-8 text will be preceded
with a BOM (Byte Order Mark). A BOM is required for correct
redirection or piping in PowerShell.
The default encoding can be changed with environment variable
DOS2UNIX_DISPLAY_ENC by setting it to "unicode", "unicodebom",
"utf8", or "utf8bom".
-f, --force
Force conversion of binary files.
-gb, --gb18030
On Windows UTF-16 files are by default converted to UTF-8,
regardless of the locale setting. Use this option to convert UTF-16
files to GB18030. This option is only available on Windows. See also
section GB18030.
-h, --help
Display help and exit.
-i[FLAGS], --info[=FLAGS] FILE ...
Display file information. No conversion is done.
The following information is printed, in this order: number of DOS
line breaks, number of Unix line breaks, number of Mac line breaks,
byte order mark, text or binary, file name.
Example output:
6 0 0 no_bom text dos.txt
0 6 0 no_bom text unix.txt
0 0 6 no_bom text mac.txt
6 6 6 no_bom text mixed.txt
50 0 0 UTF-16LE text utf16le.txt
0 50 0 no_bom text utf8unix.txt
50 0 0 UTF-8 text utf8dos.txt
2 418 219 no_bom binary dos2unix.exe
Note that sometimes a binary file can be mistaken for a text file.
See also option "-s".
Optionally extra flags can be set to change the output. One or more
flags can be added.
0 Print the file information lines followed by a null character
instead of a newline character. This enables correct
interpretation of file names with spaces or quotes when flag c
is used. Use this flag in combination with xargs(1) option -0 or
"--null".
d Print number of DOS line breaks.
u Print number of Unix line breaks.
m Print number of Mac line breaks.
b Print the byte order mark.
t Print if file is text or binary.
c Print only the files that would be converted.
With the "c" flag dos2unix will print only the files that
contain DOS line breaks, unix2dos will print only file names
that have Unix line breaks.
h Print a header.
p Show file names without path.
Examples:
Show information for all *.txt files:
dos2unix -i *.txt
Show only the number of DOS line breaks and Unix line breaks:
dos2unix -idu *.txt
Show only the byte order mark:
dos2unix --info=b *.txt
List the files that have DOS line breaks:
dos2unix -ic *.txt
List the files that have Unix line breaks:
unix2dos -ic *.txt
Convert only files that have DOS line breaks and leave the other
files untouched:
dos2unix -ic0 *.txt | xargs -0 dos2unix
Find text files that have DOS line breaks:
find -name '*.txt' -print0 | xargs -0 dos2unix -ic
-k, --keepdate
Keep the date stamp of output file same as input file.
-L, --license
Display program's license.
-l, --newline
Add additional newline.
dos2unix: Only DOS line breaks are changed to two Unix line breaks.
In Mac mode only Mac line breaks are changed to two Unix line
breaks.
unix2dos: Only Unix line breaks are changed to two DOS line breaks.
In Mac mode Unix line breaks are changed to two Mac line breaks.
-m, --add-bom
Write a Byte Order Mark (BOM) in the output file. By default an
UTF-8 BOM is written.
When the input file is UTF-16, and the option "-u" is used, an
UTF-16 BOM will be written.
Never use this option when the output encoding is other than UTF-8,
UTF-16, or GB18030. See also section UNICODE.
-n, --newfile INFILE OUTFILE ...
New file mode. Convert file INFILE and write output to file OUTFILE.
File names must be given in pairs and wildcard names should *not* be
used or you *will* lose your files.
The person who starts the conversion in new file (paired) mode will
be the owner of the converted file. The read/write permissions of
the new file will be the permissions of the original file minus the
umask(1) of the person who runs the conversion.
--no-allow-chown
Don't allow file ownership change in old file mode (default).
Abort conversion when the user and/or group ownership of the
original file can't be preserved in old file mode. See also options
"-o" and "-n". This option is only available if dos2unix has support
for preserving the user and group ownership of files.
-o, --oldfile FILE ...
Old file mode. Convert file FILE and overwrite output to it. The
program defaults to run in this mode. Wildcard names may be used.
In old file (in-place) mode the converted file gets the same owner,
group, and read/write permissions as the original file. Also when
the file is converted by another user who has write permissions on
the file (e.g. user root). The conversion will be aborted when it is
not possible to preserve the original values. Change of owner could
mean that the original owner is not able to read the file any more.
Change of group could be a security risk, the file could be made
readable for persons for whom it is not intended. Preservation of
owner, group, and read/write permissions is only supported on Unix.
To check if dos2unix has support for preserving the user and group
ownership of files type "dos2unix -V".
Conversion is always done via a temporary file. When an error occurs
halfway the conversion, the temporary file is deleted and the
original file stays intact. When the conversion is successful, the
original file is replaced with the temporary file. You may have
write permission on the original file, but no permission to put the
same user and/or group ownership properties on the temporary file as
the original file has. This means you are not able to preserve the
user and/or group ownership of the original file. In this case you
can use option "--allow-chown" to continue with the conversion:
dos2unix --allow-chown foo.txt
Another option is to use new file mode:
dos2unix -n foo.txt foo.txt
The advantage of the "--allow-chown" option is that you can use
wildcards, and the ownership properties will be preserved when
possible.
-q, --quiet
Quiet mode. Suppress all warnings and messages. The return value is
zero. Except when wrong command-line options are used.
-r, --remove-bom
Remove Byte Order Mark (BOM). Do not write a BOM in the output file.
This is the default behavior when converting to Unix line breaks.
See also option "-b".
-s, --safe
Skip binary files (default).
The skipping of binary files is done to avoid accidental mistakes.
Be aware that the detection of binary files is not 100% foolproof.
Input files are scanned for binary symbols which are typically not
found in text files. It is possible that a binary file contains only
normal text characters. Such a binary file will mistakenly be seen
as a text file.
-u, --keep-utf16
Keep the original UTF-16 encoding of the input file. The output file
will be written in the same UTF-16 encoding, little or big endian,
as the input file. This prevents transformation to UTF-8. An UTF-16
BOM will be written accordingly. This option can be disabled with
the "-ascii" option.
-ul, --assume-utf16le
Assume that the input file format is UTF-16LE.
When there is a Byte Order Mark in the input file the BOM has
priority over this option.
When you made a wrong assumption (the input file was not in UTF-16LE
format) and the conversion succeeded, you will get an UTF-8 output
file with wrong text. You can undo the wrong conversion with
iconv(1) by converting the UTF-8 output file back to UTF-16LE. This
will bring back the original file.
The assumption of UTF-16LE works as a *conversion mode*. By
switching to the default *ascii* mode the UTF-16LE assumption is
turned off.
-ub, --assume-utf16be
Assume that the input file format is UTF-16BE.
This option works the same as option "-ul".
-v, --verbose
Display verbose messages. Extra information is displayed about Byte
Order Marks and the amount of converted line breaks.
-F, --follow-symlink
Follow symbolic links and convert the targets.
-R, --replace-symlink
Replace symbolic links with converted files (original target files
remain unchanged).
-S, --skip-symlink
Keep symbolic links and targets unchanged (default).
-V, --version
Display version information and exit.
MAC MODE
In normal mode line breaks are converted from DOS to Unix and vice
versa. Mac line breaks are not converted.
In Mac mode line breaks are converted from Mac to Unix and vice versa.
DOS line breaks are not changed.
To run in Mac mode use the command-line option "-c mac" or use the
commands "mac2unix" or "unix2mac".
CONVERSION MODES
ascii
In mode "ascii" only line breaks are converted. This is the default
conversion mode.
Although the name of this mode is ASCII, which is a 7 bit standard,
the actual mode is 8 bit. Use always this mode when converting
Unicode UTF-8 files.
7bit
In this mode all 8 bit non-ASCII characters (with values from 128 to
255) are converted to a 7 bit space.
iso Characters are converted between a DOS character set (code page) and
ISO character set ISO-8859-1 (Latin-1) on Unix. DOS characters
without ISO-8859-1 equivalent, for which conversion is not possible,
are converted to a dot. The same counts for ISO-8859-1 characters
without DOS counterpart.
When only option "-iso" is used dos2unix will try to determine the
active code page. When this is not possible dos2unix will use
default code page CP437, which is mainly used in the USA. To force a
specific code page use options -437 (US), -850 (Western European),
-860 (Portuguese), -863 (French Canadian), or -865 (Nordic). Windows
code page CP1252 (Western European) is also supported with option
-1252. For other code pages use dos2unix in combination with
iconv(1). Iconv can convert between a long list of character
encodings.
Never use ISO conversion on Unicode text files. It will corrupt
UTF-8 encoded files.
Some examples:
Convert from DOS default code page to Unix Latin-1:
dos2unix -iso -n in.txt out.txt
Convert from DOS CP850 to Unix Latin-1:
dos2unix -850 -n in.txt out.txt
Convert from Windows CP1252 to Unix Latin-1:
dos2unix -1252 -n in.txt out.txt
Convert from Windows CP1252 to Unix UTF-8 (Unicode):
iconv -f CP1252 -t UTF-8 in.txt | dos2unix > out.txt
Convert from Unix Latin-1 to DOS default code page:
unix2dos -iso -n in.txt out.txt
Convert from Unix Latin-1 to DOS CP850:
unix2dos -850 -n in.txt out.txt
Convert from Unix Latin-1 to Windows CP1252:
unix2dos -1252 -n in.txt out.txt
Convert from Unix UTF-8 (Unicode) to Windows CP1252:
unix2dos < in.txt | iconv -f UTF-8 -t CP1252 > out.txt
See also <http://czyborra.com/charsets/codepages.html> and
<http://czyborra.com/charsets/iso8859.html>.
UNICODE
Encodings
There exist different Unicode encodings. On Unix and Linux Unicode files
are typically encoded in UTF-8 encoding. On Windows Unicode text files
can be encoded in UTF-8, UTF-16, or UTF-16 big endian, but are mostly
encoded in UTF-16 format.
Conversion
Unicode text files can have DOS, Unix or Mac line breaks, like regular
text files.
All versions of dos2unix and unix2dos can convert UTF-8 encoded files,
because UTF-8 was designed for backward compatibility with ASCII.
Dos2unix and unix2dos with Unicode UTF-16 support, can read little and
big endian UTF-16 encoded text files. To see if dos2unix was built with
UTF-16 support type "dos2unix -V".
On Unix/Linux UTF-16 encoded files are converted to the locale character
encoding. Use the locale(1) command to find out what the locale
character encoding is. When conversion is not possible a conversion
error will occur and the file will be skipped.
On Windows UTF-16 files are by default converted to UTF-8. UTF-8
formatted text files are well supported on both Windows and Unix/Linux.
UTF-16 and UTF-8 encoding are fully compatible, there will no text be
lost in the conversion. When an UTF-16 to UTF-8 conversion error occurs,
for instance when the UTF-16 input file contains an error, the file will
be skipped.
When option "-u" is used, the output file will be written in the same
UTF-16 encoding as the input file. Option "-u" prevents conversion to
UTF-8.
Dos2unix and unix2dos have no option to convert UTF-8 files to UTF-16.
ISO and 7-bit mode conversion do not work on UTF-16 files.
Byte Order Mark
On Windows Unicode text files typically have a Byte Order Mark (BOM),
because many Windows programs (including Notepad) add BOMs by default.
See also <http://en.wikipedia.org/wiki/Byte_order_mark>.
On Unix Unicode files typically don't have a BOM. It is assumed that
text files are encoded in the locale character encoding.
Dos2unix can only detect if a file is in UTF-16 format if the file has a
BOM. When an UTF-16 file doesn't have a BOM, dos2unix will see the file
as a binary file.
Use option "-ul" or "-ub" to convert an UTF-16 file without BOM.
Dos2unix writes by default no BOM in the output file. With option "-b"
Dos2unix writes a BOM when the input file has a BOM.
Unix2dos writes by default a BOM in the output file when the input file
has a BOM. Use option "-r" to remove the BOM.
Dos2unix and unix2dos write always a BOM when option "-m" is used.
Unicode file names on Windows
Dos2unix has optional support for reading and writing Unicode file names
in the Windows Command Prompt. That means that dos2unix can open files
that have characters in the name that are not part of the default system
ANSI code page. To see if dos2unix for Windows was built with Unicode
file name support type "dos2unix -V".
There are some issues with displaying Unicode file names in a Windows
console. See option "-D", "--display-enc". The file names may be
displayed wrongly in the console, but the files will be written with the
correct name.
Unicode examples
Convert from Windows UTF-16 (with BOM) to Unix UTF-8:
dos2unix -n in.txt out.txt
Convert from Windows UTF-16LE (without BOM) to Unix UTF-8:
dos2unix -ul -n in.txt out.txt
Convert from Unix UTF-8 to Windows UTF-8 with BOM:
unix2dos -m -n in.txt out.txt
Convert from Unix UTF-8 to Windows UTF-16:
unix2dos < in.txt | iconv -f UTF-8 -t UTF-16 > out.txt
GB18030
GB18030 is a Chinese government standard. A mandatory subset of the
GB18030 standard is officially required for all software products sold
in China. See also <http://en.wikipedia.org/wiki/GB_18030>.
GB18030 is fully compatible with Unicode, and can be considered an
unicode transformation format. Like UTF-8, GB18030 is compatible with
ASCII. GB18030 is also compatible with Windows code page 936, also known
as GBK.
On Unix/Linux UTF-16 files are converted to GB18030 when the locale
encoding is set to GB18030. Note that this will only work if the locale
is supported by the system. Use command "locale -a" to get the list of
supported locales.
On Windows you need to use option "-gb" to convert UTF-16 files to
GB18030.
GB18030 encoded files can have a Byte Order Mark, like Unicode files.
EXAMPLES
Read input from 'stdin' and write output to 'stdout':
dos2unix < a.txt
cat a.txt | dos2unix
Convert and replace a.txt. Convert and replace b.txt:
dos2unix a.txt b.txt
dos2unix -o a.txt b.txt
Convert and replace a.txt in ascii conversion mode:
dos2unix a.txt
Convert and replace a.txt in ascii conversion mode, convert and replace
b.txt in 7bit conversion mode:
dos2unix a.txt -c 7bit b.txt
dos2unix -c ascii a.txt -c 7bit b.txt
dos2unix -ascii a.txt -7 b.txt
Convert a.txt from Mac to Unix format:
dos2unix -c mac a.txt
mac2unix a.txt
Convert a.txt from Unix to Mac format:
unix2dos -c mac a.txt
unix2mac a.txt
Convert and replace a.txt while keeping original date stamp:
dos2unix -k a.txt
dos2unix -k -o a.txt
Convert a.txt and write to e.txt:
dos2unix -n a.txt e.txt
Convert a.txt and write to e.txt, keep date stamp of e.txt same as
a.txt:
dos2unix -k -n a.txt e.txt
Convert and replace a.txt, convert b.txt and write to e.txt:
dos2unix a.txt -n b.txt e.txt
dos2unix -o a.txt -n b.txt e.txt
Convert c.txt and write to e.txt, convert and replace a.txt, convert and
replace b.txt, convert d.txt and write to f.txt:
dos2unix -n c.txt e.txt -o a.txt b.txt -n d.txt f.txt
RECURSIVE CONVERSION
In a Unix shell the find(1) and xargs(1) commands can be used to run
dos2unix recursively over all text files in a directory tree. For
instance to convert all .txt files in the directory tree under the
current directory type:
find . -name '*.txt' -print0 |xargs -0 dos2unix
The find(1) option "-print0" and corresponding xargs(1) option -0 are
needed when there are files with spaces or quotes in the name. Otherwise
these options can be omitted. Another option is to use find(1) with the
"-exec" option:
find . -name '*.txt' -exec dos2unix {} \;
In a Windows Command Prompt the following command can be used:
for /R %G in (*.txt) do dos2unix "%G"
PowerShell users can use the following command in Windows PowerShell:
get-childitem -path . -filter '*.txt' -recurse | foreach-object {dos2unix $_.Fullname}
LOCALIZATION
LANG
The primary language is selected with the environment variable LANG.
The LANG variable consists out of several parts. The first part is
in small letters the language code. The second is optional and is
the country code in capital letters, preceded with an underscore.
There is also an optional third part: character encoding, preceded
with a dot. A few examples for POSIX standard type shells:
export LANG=nl Dutch
export LANG=nl_NL Dutch, The Netherlands
export LANG=nl_BE Dutch, Belgium
export LANG=es_ES Spanish, Spain
export LANG=es_MX Spanish, Mexico
export LANG=en_US.iso88591 English, USA, Latin-1 encoding
export LANG=en_GB.UTF-8 English, UK, UTF-8 encoding
For a complete list of language and country codes see the gettext
manual:
<http://www.gnu.org/software/gettext/manual/html_node/Usual-Language
-Codes.html>
On Unix systems you can use the command locale(1) to get locale
specific information.
LANGUAGE
With the LANGUAGE environment variable you can specify a priority
list of languages, separated by colons. Dos2unix gives preference to
LANGUAGE over LANG. For instance, first Dutch and then German:
"LANGUAGE=nl:de". You have to first enable localization, by setting
LANG (or LC_ALL) to a value other than "C", before you can use a
language priority list through the LANGUAGE variable. See also the
gettext manual:
<http://www.gnu.org/software/gettext/manual/html_node/The-LANGUAGE-v
ariable.html>
If you select a language which is not available you will get the
standard English messages.
DOS2UNIX_LOCALEDIR
With the environment variable DOS2UNIX_LOCALEDIR the LOCALEDIR set
during compilation can be overruled. LOCALEDIR is used to find the
language files. The GNU default value is "/usr/local/share/locale".
Option --version will display the LOCALEDIR that is used.
Example (POSIX shell):
export DOS2UNIX_LOCALEDIR=$HOME/share/locale
RETURN VALUE
On success, zero is returned. When a system error occurs the last system
error will be returned. For other errors 1 is returned.
The return value is always zero in quiet mode, except when wrong
command-line options are used.
STANDARDS
<http://en.wikipedia.org/wiki/Text_file>
<http://en.wikipedia.org/wiki/Carriage_return>
<http://en.wikipedia.org/wiki/Newline>
<http://en.wikipedia.org/wiki/Unicode>
AUTHORS
Benjamin Lin - <blin@socs.uts.edu.au>, Bernd Johannes Wuebben (mac2unix
mode) - <wuebben@kde.org>, Christian Wurll (add extra newline) -
<wurll@ira.uka.de>, Erwin Waterlander - <waterlan@xs4all.nl>
(maintainer)
Project page: <http://waterlan.home.xs4all.nl/dos2unix.html>
SourceForge page: <http://sourceforge.net/projects/dos2unix/>
SEE ALSO
file(1) find(1) iconv(1) locale(1) xargs(1)