Node:C Function Headings, Previous:Specified Headings, Up:Sections
To show in which functions differences occur for C and similar
languages, you can use the -p or --show-c-function option.
This option automatically defaults to the context output format
(see Context Format), with the default number of lines of context.
You can override that number with -C lines elsewhere in the
command line. You can override both the format and the number with
-U lines elsewhere in the command line.
The -p and --show-c-function options are equivalent to
-F '^[[:alpha:]$_]' if the unified format is specified, otherwise
-c -F '^[[:alpha:]$_]' (see Specified Headings). GNU
diff provides them for the sake of convenience.