sqp and glpk

[Henry Bock]

Hi,

I'm trying to minimize a nonlinear function with an inequality
constraint:

#! /usr/local/bin/octave -qf

function obj = phi (x)
        obj = x**4-x**2;
endfunction

function u = h (x)
         u = -((x-1)**2-1);
endfunction
          
x0 = [1.7];
         
[x, obj, info, iter, nf, lambda] = sqp (x0, @phi,[],@h)

Unfortunately I'm getting the following error:
error: libglpk.so.0: cannot open shared object file: No such file or
directory
error: `__glpk__' undefined near line 524 column 5
error: called from `glpk' in file
`/usr/local/share/octave/2.9.12/m/optimization/glpk.m'
error: evaluating if command near line 224, column 4
error: evaluating if command near line 209, column 2
error: evaluating if command near line 207, column 7
error: evaluating if command near line 192, column 5
error: evaluating if command near line 79, column 3
error: called from `qp' in file
`/usr/local/share/octave/2.9.12/m/optimization/qp.m'
error: evaluating while command near line 284, column 5
error: evaluating if command near line 175, column 3
error: called from `sqp' in file
`/usr/local/share/octave/2.9.12/m/optimization/sqp.m'
error: near line 15 of file `./test2'

I have installed (I think) glpk 4.19 and I also reinstalled octave but
the error message doesn't seem to change.

I would appreciate any help very much!

Thanks,
Henry

p.s. I would classify myself as a user with very limited  background
knowledge.