dos2unix (1)

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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 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 (

) followed by a Line Feed (). In Unix text files a line break is a single character: the Line Feed (). In Mac text files, prior to Mac a line break was single Carriage Return () character. Nowadays Mac uses Unix style () line breaks.

Besides line breaks Dos2unix can also convert the encoding of files. A few

code pages can be converted to Unix Latin-1. And Windows Unicode () files can be converted to Unix Unicode () 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

-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.

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 -ic *.txt | xargs dos2unix

Find text files that have

DOS

line breaks:

    find -name '*.txt' | xargs 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.

-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.

-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 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.

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 <czyborra.com/charsets/codepages.html> and <czyborra.com/charsets/iso8859.html>.

UNICODE

Encodings

There exist different Unicode encodings. On Unix and Linux Unicode files are typically encoded in encoding. On Windows Unicode text files can be encoded in or big endian, but are mostly encoded in format.

Conversion

Unicode text files can have Unix or Mac line breaks, like regular text files.

All versions of dos2unix and unix2dos can convert

encoded files, because was designed for backward compatibility with

Dos2unix and unix2dos with Unicode

support, can read little and big endian encoded text files. To see if dos2unix was built with support type "dos2unix -V".

On Unix/Linux

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

files are by default converted to formatted text files are well supported on both Windows and Unix/Linux.

and encoding are fully compatible, there will no text be lost in the conversion. When an to conversion error occurs, for instance when the input file contains an error, the file will be skipped.

When option "-u" is used, the output file will be written in the same

encoding as the input file. Option "-u" prevents conversion to

Dos2unix and unix2dos have no option to convert

files to

and 7-bit mode conversion do not work on files.

Byte Order Mark

On Windows Unicode text files typically have a Byte Order Mark (), because many Windows programs (including Notepad) add BOMs by default. See also <en.wikipedia.org/wiki/Byte_order_mark>.

On Unix Unicode files typically don't have a

It is assumed that text files are encoded in the locale character encoding.

Dos2unix can only detect if a file is in

format if the file has a When an file doesn't have a dos2unix will see the file as a binary file.

Use option "-ul" or "-ub" to convert an

file without

Dos2unix writes by default no

in the output file. With option "-b" Dos2unix writes a when the input file has a

Unix2dos writes by default a

in the output file when the input file has a Use option "-r" to remove the

Dos2unix and unix2dos write always a

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 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 (with ) to Unix

    dos2unix -n in.txt out.txt

Convert from Windows

(without ) to Unix

    dos2unix -ul -n in.txt out.txt

Convert from Unix

to Windows with

    unix2dos -m -n in.txt out.txt

Convert from Unix

to Windows

    unix2dos < in.txt | iconv -f UTF-8 -t UTF-16 > out.txt

GB18030

is a Chinese government standard. A mandatory subset of the standard is officially required for all software products sold in China. See also <en.wikipedia.org/wiki/GB_18030>.

is fully compatible with Unicode, and can be considered an unicode transformation format. Like is compatible with is also compatible with Windows code page 936, also known as

On Unix/Linux

files are converted to when the locale encoding is set to 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

files to

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

Use dos2unix in combination with the find(1) and xargs(1) commands to recursively convert text files in a directory tree structure. For instance to convert all .txt files in the directory tree under the current directory type:

    find . -name '*.txt' |xargs 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: <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: <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

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

<en.wikipedia.org/wiki/Text_file>

<en.wikipedia.org/wiki/Carriage_return>

<en.wikipedia.org/wiki/Newline>

<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: <waterlan.home.xs4all.nl/dos2unix.html>

SourceForge page: <sourceforge.net/projects/dos2unix>

SEE ALSO

file(1) find(1) iconv(1) locale(1) xargs(1)