I am learning how to run programs through the terminal on Mac, and I tried running one of my programs:

clang++ /.../file.cpp
clang++ -c /.../file.cpp

and each time I get an error telling me the compiler can’t find the file in the standard library.

10: fatal error: 'iostream' file not found
    1 | #include <iostream>
      |          ^~~~~~~~~~

The same error shows if I replace clang++ with g++, clang, and gcc.

After researching, I used cpp -v to find where my compiler/computer is looking. I downloaded clang directly from LLVM GitHub, and I then tried using --stdlib and --stdlib++-isystem to attempt to redirect the compiler’s search, but each time I use it I get an error message

cpp --stdlib++-isystem <filepath of 'include' directory that contains library>
cc: error: no input files

I would guess that I’m doing things wrong, but I don’t know what I don’t know to fix the problem. Any help?