zig/test/standalone/load_dynamic_library/main.zig

const std = @import("std");

pub fn main(init: std.process.Init) !void {
    const args = try init.minimal.args.toSlice(init.arena.allocator());

    const dynlib_name = args[1];

    var lib = try std.DynLib.open(dynlib_name);
    defer lib.close();

    const Add = *const fn (i32, i32) callconv(.c) i32;
    const addFn = lib.lookup(Add, "add") orelse return error.SymbolNotFound;

    const result = addFn(12, 34);
    std.debug.assert(result == 46);
}