Useful diff and patch commands:
Create a patch with 3 lines of context and amount of blank lines. I want to see other whitespace difference – it might expose a typo.
diff -u 3 oldfile newfile > patchfile
Use CVS diff to create a patch comparing the local file (newer) with the repository version.
cvs diff -up file > patchfile
Patch a file and create an orig copy (from http://gentoo-wiki.com/MAN_patch_1 ). The -B option allows the prefix for a file – in this case I’ll save it somewhere else as a patched file.
patch -b < patchfile patch -B /home/user/patched < patchfile
Patch a file you specify
patch file_to_be_patched patchfile
Diff notes
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# diff -h
usage: man [-c|-f|-k|-w|-tZT device] [-i|-I] [-adlhu7V] [-Mpath] [-Ppager]
[-Cfile] [-Slist] [-msystem] [-pstring] [-Llocale] [-eextension]
[section] page ...
-a, --all find all matching manual pages.
-d, --debug emit debugging messages.
-e, --extension limit search to extension type `extension'.
-f, --whatis equivalent to whatis.
-k, --apropos equivalent to apropos.
-w, --where, --location print physical location of man page(s).
-W, --where-cat,
--location-cat print physical location of cat file(s).
-l, --local-file interpret `page' argument(s) as local filename(s).
-u, --update force a cache consistency check.
-i, --ignore-case look for pages case-insensitively (default).
-I, --match-case look for pages case-sensitively.
-r, --prompt string provide the `less' pager with a prompt
-c, --catman used by catman to reformat out of date cat pages.
-7, --ascii display ASCII translation of certain latin1 chars.
-E, --encoding encoding use the selected nroff device and display in pager.
-t, --troff use groff to format pages.
-T, --troff-device device use groff with selected device.
-H, --html use lynx or argument to display html output.
-Z, --ditroff use groff and force it to produce ditroff.
-X, --gxditview use groff and display through gditview (X11):
-X = -TX75, -X100 = -TX100, -X100-12 = -TX100-12.
-D, --default reset all options to their default values.
-C, --config-file file use this user configuration file.
-M, --manpath path set search path for manual pages to `path'.
-P, --pager pager use program 'pager' to display output.
-S, --sections list use colon separated section list.
-m, --systems system search for man pages from other unix system(s).
-L, --locale locale define the locale for this particular man search.
-p, --preprocessor string string indicates which preprocessors to run.
e - [n]eqn p - pic t - tbl
g - grap r - refer v - vgrind
-V, --version show version.
-h, --help show this usage message.
