View source for Unix2dos

{{sources|date=November 2020}}
{{lowercase}}
{{Infobox software
| name                   = unix2dos & dos2unix
| logo                   = 
| screenshot             = 
| screenshot size        = 
| caption                = 
| author                 = John Birchfield
| developer              = Benjamin Lin, Bernd Johannes Wuebben, Christian Wurll, Erwin Waterlander
| released               = {{Start date and age|1989}}
| latest release version = {{wikidata|property|preferred|references|edit|P348|P548=Q2804309}}
| latest release date    = {{Start date and age|{{wikidata|qualifier|preferred|single|P348|P548=Q2804309|P577}}|df=yes}}
| operating system       = [[Unix-like]], [[DOS]], [[OS/2]], [[Microsoft Windows|Windows]]
| platform               = [[Cross-platform]]
| genre                  = [[Command (computing)|Command]]
| license                = [[FreeBSD]] style license
| website                = {{URL|https://waterlan.home.xs4all.nl/dos2unix.html}}
}}
'''{{code|unix2dos}}''' (sometimes named {{code|todos}} or {{code|u2d}}) is a tool to convert [[Newline|line breaks]] in a [[text file]] from [[Unix]] format (Line feed) to [[DOS]] format ([[carriage return]] + Line feed) and vice versa.  When invoked as {{code|unix2dos}} the program will convert a Unix text file to DOS format, when invoked as {{code|dos2unix}} it will convert a DOS text file to Unix format.<ref>A practical guide to Linux. Mark G. Sobell {{ISBN|0-13-147823-0}} Page 55</ref>

==Usage==
Unix2dos and dos2unix are not part of the Unix standard. Commercial Unixes usually come with their own implementation of unix2dos/dos2unix, like SunOS/Solaris's ''dos2unix/unix2dos'', HP-UX's ''dos2ux/ux2dos'' and Irix's ''to_unix/to_dos''.

There exist many open source alternatives with different command names and options like ''dos2unix/unix2dos'', ''d2u/u2d'', ''{{Not a typo|fromdos/todos}}'', ''endlines'', ''flip''. The multi-call binary [[busybox]] includes an implementation of ''unix2dos/dos2unix''.

See the [[Man page|manual page]] of the respective commands.

==Alternatives to unix2dos conversion==
{{blist
|recode <syntaxhighlight lang="console">
$ recode latin1..dos file
</syntaxhighlight>
| Open the file with Windows Write ([[WordPad]]) or Microsoft Word, and save in "plain text" format.
| Similar results can be achieved with different Unix tools to change the trailing newline '\n' to a combination of carriage return and newline characters '\r\n', for example with [[perl]]  or the GNU implementation of [[sed]] in-line editing:
* <syntaxhighlight lang="console" inline>
$ perl -i -p -e 's|[\r\n]+|\r\n|g' file
</syntaxhighlight>
* <syntaxhighlight lang="console" inline>
$ sed -i -n -z 's/\r*\n/\r\n/g;p' file
</syntaxhighlight>
}}

==Alternatives to dos2unix conversion==
For the opposite conversion ({{mono|[[dos2unix]]}}) it is possible to use, for example, the utility [[tr (Unix)|tr]] with the {{code|-d '\r'}} flag to remove the carriage return characters:
* <syntaxhighlight lang="console" inline>
$ tr -d '\r' < file > file2 # For ASCII and other files which do not contain multibyte characters (Not utf-8 safe).
</syntaxhighlight>
* <syntaxhighlight lang="console" inline>
$ perl -i -p -e 's/\r//g' file
</syntaxhighlight>
* <syntaxhighlight lang="console" inline>
$ sed -i -e 's/\r//g' file
</syntaxhighlight>

Note: The above method assumes there are only DOS line breaks in the input file. Any Mac line breaks (\r) present in the input will be removed.

An alternative to the dos2unix conversion is possible by using the {{code|col}} command that is available on [[Linux]] and other Unix-like operating systems, including Mac OS X.  In the following case, InFile contains the undesired DOS (^M) line endings.  After execution, OutFile is either created or replaced, and contains UNIX line endings.  The {{code|-b}} option tells {{code|col}} not to output backspace characters.
<syntaxhighlight lang="console">
$ col -b < InFile > OutFile
</syntaxhighlight>

==See also==
* [[Newline]]

==References==
{{Reflist}}

==External links==
* [http://www.thefreecountry.com/tofrodos/ Tofrodos] - software that provides dos2unix and unix2dos
* [http://waterlan.home.xs4all.nl/dos2unix.html Dos2Unix] - Dos2Unix / Unix2Dos - Text file format converters

{{Unix commands}}

[[Category:System administration]]
[[Category:Unix text processing utilities]]


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