-o FILE --output=FILE Operate interactively, sending output to FILE.
-i --ignore-case Consider upper- and lower-case to be the same.
-E --ignore-tab-expansion Ignore changes due to tab expansion.
-b --ignore-space-change Ignore changes in the amount of white space.
-W --ignore-all-space Ignore all white space.
-B --ignore-blank-lines Ignore changes whose lines are all blank.
-I RE --ignore-matching-lines=RE Ignore changes whose lines all match RE.
--strip-trailing-cr Strip trailing carriage return on input.
-a --text Treat all files as text.
-w NUM --width=NUM Output at most NUM (default 130) columns per line.
-l --left-column Output only the left column of common lines.
-s --suppress-common-lines Do not output common lines.
-t --expand-tabs Expand tabs to spaces in output.
-d --minimal Try hard to find a smaller set of changes.
-H --speed-large-files Assume large files and many scattered small changes.
--diff-program=PROGRAM Use PROGRAM to compare files.
-v --version Output version info.
--help Output this help.
If a FILE is `-', read standard input.
This program comes with NO WARRANTY, to the extent permitted by law. You may redistribute copies of this program under the terms of the GNU General Public License. For more information about these matters, see the file named COPYING.
should give you access to the complete manual.