dos2unix - DOS/Mac to Unix and vice versa text file format converter
dos2unix [options] [FILE ...] [-n INFILE OUTFILE ...]
unix2dos [options] [FILE ...] [-n INFILE OUTFILE ...]
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.
- --
- 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.
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".
- 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>.
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.
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.
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.
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.
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 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.
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
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 $_.Fullname}
- LANG
- The primary language is selected with the environment
variable LANG. The LANG variable consists out of several parts. The first
part is in small letters the language code. The second is optional and is
the country code in capital letters, preceded with an underscore. There is
also an optional third part: character encoding, preceded with a dot. A
few examples for POSIX standard type shells:
export LANG=nl Dutch
export LANG=nl_NL Dutch, The Netherlands
export LANG=nl_BE Dutch, Belgium
export LANG=es_ES Spanish, Spain
export LANG=es_MX Spanish, Mexico
export LANG=en_US.iso88591 English, USA, Latin-1 encoding
export LANG=en_GB.UTF-8 English, UK, UTF-8 encoding
For a complete list of language and country codes see the gettext manual:
<http://www.gnu.org/software/gettext/manual/html_node/Usual-Language-Codes.html>
On Unix systems you can use the command locale(1) to get locale
specific information.
- LANGUAGE
- With the LANGUAGE environment variable you can specify a
priority list of languages, separated by colons. Dos2unix gives preference
to LANGUAGE over LANG. For instance, first Dutch and then German:
"LANGUAGE=nl:de". You have to first enable localization, by
setting LANG (or LC_ALL) to a value other than "C", before you
can use a language priority list through the LANGUAGE variable. See also
the gettext manual:
<http://www.gnu.org/software/gettext/manual/html_node/The-LANGUAGE-variable.html>
If you select a language which is not available you will get the standard
English messages.
- DOS2UNIX_LOCALEDIR
- With the environment variable DOS2UNIX_LOCALEDIR the
LOCALEDIR set during compilation can be overruled. LOCALEDIR is used to
find the language files. The GNU default value is
"/usr/local/share/locale". Option --version will display
the LOCALEDIR that is used.
Example (POSIX shell):
export DOS2UNIX_LOCALEDIR=$HOME/share/locale
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.
<
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>
Benjamin Lin - <
[email protected]>, Bernd Johannes Wuebben (mac2unix
mode) - <
[email protected]>, Christian Wurll (add extra newline) -
<
[email protected]>, Erwin Waterlander - <
[email protected]>
(maintainer)
Project page: <
http://waterlan.home.xs4all.nl/dos2unix.html>
SourceForge page: <
http://sourceforge.net/projects/dos2unix/>
file(1) find(1) iconv(1) locale(1)
xargs(1)