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

Default conversion mode. See also section CONVERSION MODES.

-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.

-e, --add-eol

Add a line break to the last line if there isn't one. This works for every conversion.

A file converted from DOS to Unix format may lack a line break on the last line. There are text editors that write text files without a line break on the last line. Some Unix programs have problems processing these files, because the POSIX standard defines that every line in a text file must end with a terminating newline character. For instance concatenating files may not give the expected result.

-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".

If in addition option "-e" or "--add-eol" is used also the type of the line break of the last line is printed, or "noeol" if there is none.

Example output:

     6       0       0  no_bom    text   dos     dos.txt
     0       6       0  no_bom    text   unix    unix.txt
     0       0       6  no_bom    text   mac     mac.txt
     1       0       0  no_bom    text   noeol   noeol_dos.txt
    

Optionally extra flags can be set to change the output. One or more flags can be added.

    dos2unix -i *.txt

    dos2unix -idu *.txt

    dos2unix --info=b *.txt

    dos2unix -ic *.txt

    unix2dos -ic *.txt

    dos2unix -e -ic *.txt

    dos2unix -ic0 *.txt | xargs -0 dos2unix

    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.

--no-add-eol

Do not add a line break to the last line if there isn't one.

-O, --to-stdout

Write to standard output, like a Unix filter. Use option "-o" to go back to old file (in-place) mode.

Combined with option "-e" files can be properly concatenated. No merged last and first lines, and no Unicode byte order marks in the middle of the concatenated file. Example:

    dos2unix -e -O file1.txt file2.txt > output.txt
    

-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

By default 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

This is the default conversion mode. This mode is for converting ASCII and ASCII-compatible encoded files, like UTF-8. Enabling ascii mode disables 7bit and iso mode.

If dos2unix has UTF-16 support, UTF-16 encoded files are converted to the current locale character encoding on POSIX systems and to UTF-8 on Windows. Enabling ascii mode disables the option to keep UTF-16 encoding ("-u") and the options to assume UTF-16 input ("-ul" and "-ub"). To see if dos2unix has UTF-16 support type "dos2unix -V". See also section UNICODE.

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

    dos2unix -n in.txt out.txt

    dos2unix -ul -n in.txt out.txt

    unix2dos -m -n in.txt out.txt

    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 <https://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: <https://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: <https://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

<https://en.wikipedia.org/wiki/Text_file>

<https://en.wikipedia.org/wiki/Carriage_return>

<https://en.wikipedia.org/wiki/Newline>

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

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

SEE ALSO

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