How to call C from Swift?

Question

Is there a way to call C routines from Swift?

A lot of iOS / Apple libraries are C only and I\'d still like to be able to call those.

For example, I\'d like

Answer 1

In the case of c++, there is this error that pops up:

  "_getInput", referenced from: 

You need a c++ header file too. Add c-linkage to your function, then include the header file in the bridge-header:

Swift 3

UserInput.h

#ifndef USERINPUT_H
#define USERINPUT_H    

#ifdef __cplusplus
extern "C"{
#endif

getInput(int *output);

#ifdef __cplusplus
}
#endif

UserInput.c

#include 

void getInput(int *output) {
    scanf("%i", output);
}    

main.swift

import Foundation
var output: CInt = 0
getInput(&output)
print(output)

cliinput-Bridging-Header.h

#include "UserInput.h"

Here is the original video explaining this