showchar­in­box – Show char­ac­ters in­side a box

The pack­age type­sets a char­ac­ter in­side a box, show­ing where ref­er­ence point is, and dis­play­ing width, height, and depth in­for­ma­tion of the char­ac­ter.
The out­put is like that on page 63 of “The TeXBook” or page 101 of “The METAFONT­book”. The pack­age it­self is mo­ti­vated by Knuth’s macros in the file man­mac.tex.
Users should note that us­ing a small size for the char­ac­ter in­side the box does not make any sense: use a large size.