This article needs additional citations for
verification. (November 2020) |
Original author(s) | John Birchfield |
---|---|
Developer(s) | Benjamin Lin, Bernd Johannes Wuebben, Christian Wurll, Erwin Waterlander |
Initial release | 1989 |
Stable release | 7.5.2
[1]
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Repository | |
Operating system | Unix-like, DOS, OS/2, Windows |
Platform | Cross-platform |
Type | Command |
License | FreeBSD style license |
Website |
waterlan |
unix2dos
(sometimes named todos
or u2d
) is a tool to convert
line breaks in a
text file from
Unix format (Line feed) to
DOS format (
carriage return + Line feed) and vice versa. When invoked as unix2dos
the program will convert a Unix text file to DOS format, when invoked as dos2unix
it will convert a DOS text file to Unix format.
[2]
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, fromdos/todos, endlines, flip. The multi-call binary busybox includes an implementation of unix2dos/dos2unix.
See the manual page of the respective commands.
$ recode latin1..dos file
$ perl -i -p -e 's|[\r\n]+|\r\n|g' file
$ sed -i -e 's/\r*$/\r/' file
For the opposite conversion (
dos2unix) it is possible to use, for example, the utility
tr with the -d '\r'
flag to remove the carriage return characters:
$ tr -d '\r' < file > file2 # For ASCII and other files which do not contain multibyte characters (Not utf-8 safe).
$ perl -i -p -e 's/\r//g' file
$ sed -i -e 's/\r//g' file
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 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 -b
option tells col
not to output backspace characters.
$ col -b < InFile > OutFile