zptsvx(3) on Linux
The text d2b54cfb5ed2, as Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
use the factorization A = L*D*L**H to compute the solution to a complex system of linear equations A*X = B, where A is an N-by-N Hermitian positive definite tridiagonal matrix and X and B are N-by-NRHS matrices