Patching multiplier files
dry run (check first)
patch -p1 --dry-run -i 323cc165b663a078c50da10ca9d79c48feddd4a4.patch
patch multiplier files
patch -p1 -i 323cc165b663a078c50da10ca9d79c48feddd4a4.patch
patch single file
patch foo.c < patch.diff
Undo patch
patch -R < /path/to/file
more sources
http://www.cyberciti.biz/faq/appy-patch-file-using-patch-command/