I'm looking for something like cflow but for C++.
ctags helps us find the definition. I want to find the callers, which is the reverse problem.
Doxygen, which can be invoked from the command line once you have produced a doxyfile, can produce caller graph for all, or selected, functions/methods, in a given code project but these are normally viewed in a browser. You will also need the GraphViz DOT tool.