Select nested lists based on string pattern

Question

I would like to select nested lists out of a master list based on certain string pattern as in the following example:

lis = {{a, b, c, d}, {xy, y, z, w}, {e, f, g, h}, {xz, f, g, h}};

I would like to create a list with all nested lists starting with x* in the fist position.

I tried the following functions:

Cases[lis, {q_, r__} /; StringMatchQ[q, "x*"] -> {q, r}]

or

Select[lis2, First[#] == x &]

Both do not work.

Does anyone can give me a hint?

Answer 1

Just get the symbol's name and match for that:

Cases[lis, {q_, r__} /; StringMatchQ[SymbolName[q], "x*"] -> {q, r}]
(* {{xy, y, z, w}, {xz, f, g, h}} *)

or using Select:

Select[lis, First@Characters[SymbolName[First@#]] == "x" &]