Three versions of the dos2unix program, which converts line endings
between the DOS-style CRLF and Unix-style LF.


Ubuntu Linux:
========================================================================
$ dos2unix -h
tofrodos Ver 1.7.8 Converts text files between DOS and Unix formats.
Copyright 1996-2008 by Christopher Heng. All rights reserved.
Usage: dos2unix [options] [file...]
-a	Always convert (DOS to Unix: kill all CRs;
	Unix to DOS: convert all LFs to CRLFs)
-b	Make backup of original file (.bak).
-d	Convert DOS to Unix.
-e	Abort processing files on error in any file.
-f	Force: convert even if file is not writeable.
-h	Display help on usage and quit.
-l file	Log most errors and verbose messages to <file>
-o	Overwrite original file (no backup).
-p	Preserve file owner and time.
-u	Convert Unix to DOS.
-v	Verbose.
-V	Show version and quit.


Arch Linux:
========================================================================
$ dos2unix -h
usage:
	dos2unix [--verbose|-v] [--test|-t] [--force|-f] \
		[--<x>2<y>|--auto|-<Z>] \
		[<file name> [...]]
where:
	--auto, -A	output will be set based upon auto-detection
			of source format
	--d2u, -U	perform DOS -> UNIX conversion
	--m2u, -T	perform MAC -> UNIX conversion
	--u2d, -D	perform UNIX -> DOS conversion
	--u2m, -M	perform UNIX -> MAC conversion
	--d2m, -O	perform DOS -> MAC conversion
	--m2d, -C	perform MAC -> DOS conversion

	--force		suppress internal conversion type corrections
			based on autodetected input format
	--skipbin, -b	skip binary files
	--test, -t	don't write any conversion results; useful with
			--verbose to just report on source type
	--verbose, -v	print extra information on stderr
	--version, -V	print version information on stderr

- when no options are given then input format will be automatically detected
  and converted as follows:
	DOS -> UNIX
	MAC -> UNIX
	UNIX -> DOS
- same as above applies if --auto option is used
- when no file is given, then stdin is used as input and stdout as output
- binary files will be skipped automatically if option --skipbin
  (or -b) is used
- stray '\r' characters (without a following '\n') in files in DOS format are
  reported but only conversion 'DOS -> Unix' affects them (they are skipped)
- stray '\n' characters in files in MAC format are not detected for now


Mac OSX (FreeBSD):
========================================================================
dos2unix 5.1.1 (2010-08-18)
Usage: dos2unix [-fhkLlqV] [-c convmode] [-o file ...] [-n infile outfile ...]
 -c --convmode    conversion mode
  convmode       ascii, 7bit, iso, mac, default to ascii
 -f --force       force conversion of all files
 -h --help        give this help
 -k --keepdate    keep output file date
 -L --license     display software license
 -l --newline     add additional newline
 -n --newfile     write to new file
  infile         original file in new file mode
  outfile        output file in new file mode
 -o --oldfile     write to old file
  file ...       files to convert in old file mode
 -q --quiet       quiet mode, suppress all warnings
                 always on in stdio mode
 -V --version     display version number


NetBSD:
========================================================================
$ dos2unix -h
dos2unix: unknown option -- h
usage: dos2unix [-p] [file ...]