I write simple header file when I compile I get the error
我编译时编写简单的头文件我得到了错误
/tmp/ccOH3HcX.o: In function `main':
sample.c:(.text+0x15): undefined reference to `f'
collect2: error: ld returned 1 exit status
whatever.h
#ifndef WHATEVER_H_INCLUDED
#define WHATEVER_H_INCLUDED
int f(int a);
#endif
Example whatever.c
#include "whatever.h"
int f(int a) { return a + 1; }
sample.c
#include "whatever.h"
int main(int argc, char **argv)
{
printf("%d\n", f(2)); /* prints 3 */
return 0;
}
To compile it :
要编译它:
$ gcc -c whatever.c -o whatever.o
$ gcc -c sample.c -o sample.o
2 个解决方案
#1
You need to include the object file whatever.o on the second gcc compilation line.
您需要在第二个gcc编译行中包含目标文件whatever.o。
A simple gcc whatever.c sample.c -o sample should do it
一个简单的gcc whatever.c sample.c -o sample应该这样做
#2
The compiler steps you gave only create object files, not an executable. I suppose you did something like
您只给出了创建对象文件的编译器步骤,而不是可执行文件。我想你做了类似的事情
gcc sample.c -o sample
afterwards and then got the error?
之后然后得到了错误?
You have to link the object files to get an executable, like so:
您必须链接目标文件以获取可执行文件,如下所示:
gcc whatever.o sample.o -o executable_file
#1
You need to include the object file whatever.o on the second gcc compilation line.
您需要在第二个gcc编译行中包含目标文件whatever.o。
A simple gcc whatever.c sample.c -o sample should do it
一个简单的gcc whatever.c sample.c -o sample应该这样做
#2
The compiler steps you gave only create object files, not an executable. I suppose you did something like
您只给出了创建对象文件的编译器步骤,而不是可执行文件。我想你做了类似的事情
gcc sample.c -o sample
afterwards and then got the error?
之后然后得到了错误?
You have to link the object files to get an executable, like so:
您必须链接目标文件以获取可执行文件,如下所示:
gcc whatever.o sample.o -o executable_file