d2u

Convert a file from DOS to Unix line endings

$ d2u [file.txt]

$ d2u [file1.txt] [file2.txt] [file3.txt]

$ d2u -b [file.txt]

$ d2u -b -e [.bak] [file.txt]

$ d2u -n [file.txt]

$ d2u -q [file.txt]

d2u [options] [file...]

d2u converts text files from DOS/Windows line endings (CRLF - Carriage Return + Line Feed) to Unix line endings (LF - Line Feed only). It is an alias or alternative name for the dos2unix utility.
The tool modifies files in place by default, making it convenient for batch conversion. It automatically detects binary files and skips them unless forced. Multiple files can be processed in a single command.
This conversion is commonly needed when transferring text files from Windows to Unix/Linux systems, or when working with files that have mixed line endings from version control systems.

FILE

File(s) to convert. Converts in place by default.

Keep backup of original file.

Backup file extension (default: .bak).

Show what would be done without changing files.

Quiet mode, suppress output.

Preserve original file timestamp.

Force conversion even on binary files.

Display help information.

Binary files may be corrupted if converted; the tool attempts to detect and skip them. In-place conversion without backup can lose original data. Some files may have intentional CRLF sequences that should not be converted.

d2u is typically an alias for dos2unix, which has been a standard Unix utility for decades. The need for line ending conversion arose from the different conventions adopted by CP/M, DOS, and Unix in the late 1970s and 1980s.

dos2unix(1), unix2dos(1), u2d(1), tr(1)