Implement whereis #396
Description
Implementing https://github.com/util-linux/util-linux/blob/master/misc-utils/whereis.1.adoc
I'll am taking this up, but facing the following issue:
The search restrictions (options -b, -m and -s) are cumulative and apply to the subsequent name patterns on the command line. Any new search restriction resets the search mask. For example,
whereis -bm ls tr -m gcc
searches for "ls" and "tr" binaries and man pages, and for "gcc" man pages only.
whereis has sticky, resettable options and clap doesn't have a clear support for doing the same.
(The approach would be to use .trailing_var_arg(true) and use a simple match as in the original C source. This defeats the purpose of clap)