It is sometimes useful to access your own C or Fortran programs using shell escape functions. Shell escape functions use the shell escape command ! to make external stand-alone programs act like new MATLAB® functions.
For example, the following function, garfield.m, uses an external function, gareqn, to find the solution to Garfield's equation.
function y = garfield(a,b,q,r) save gardata a b q r !gareqn load gardata
For more information, see Run External Commands, Scripts, and Programs.