如何在其他文件中使用var，函数和结构？

Question

In timer.c I have

typedef struct Timer {

    int startTicks;
    int pausedTicks;

    int paused;
    int started;

} Timer;

void Init( Timer *t )
{
    t->startTicks = 0;
    t->pausedTicks = 0;
    t->paused = 0;
    t->started = 0;
}

What do i need to do in main.c to make use of this struct and functions in that file?

Answer 1

In general, .c files contain definitions and .h files contain declarations. A better approach would be to keep your definitions in a header:

//timer.h
#ifndef TIMER_H //include guard
#define TIMER_H

typedef struct Timer { //struct declaration

    int startTicks;
    int pausedTicks;

    int paused;
    int started;

} Timer;

void Init( Timer *t ); //method declaration

#endif


//timer.c
#include "timer.h"

void Init( Timer *t ) //method definition
{
    t->startTicks = 0;
    t->pausedTicks = 0;
    t->paused = 0;
    t->started = 0;
}

//main.c
#include "timer.h"  //include declarations
int main()
{
    Timer* t = malloc(sizeof(Timer));
    Init(t);
    free(t);
    return 0;
}

Answer 2

Learn to use header files (usually named *.h ) and #include them.

Learn how to compile a program with several compilation units, eg with a Makefile .

Don't forget to enable all warnings and debugging information (with GCC, that means gcc -g -Wall , ie CFLAGS=-g -Wall in your Makefile ).