未定义的引用'的shm_open“，已经在这里添加-lrt标志 [英] undefined reference 'shm_open', already add -lrt flag here

问题描述

我只是有一个系统崩溃，并重新安装的Ubuntu 11.10，和我的code产生这种奇怪的错误。

I just have a system crash and reinstall Ubuntu 11.10, and my code produces this strange error.

我写了一个简单的code样品测试的问题所在：

I wrote a simple code sample to test where the problem is:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>

int main (void) {

    int i;

    i = shm_open ("/tmp/shared", O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);   printf ("shm_open rc = %d\n", i);

    shm_unlink ("/tmp/shared");

    return (0);
}

和编译命令是

的gcc -lrt -o test.c的测试

该错误是：

/tmp/ccxVIUiP.o: In function `main':
test.c:(.text+0x21): undefined reference to `shm_open'
test.c:(.text+0x46): undefined reference to `shm_unlink'
collect2: ld returned 1 exit status

我已经添加-lrt lib下，为何仍不能编译？

I have already added -lrt lib, why does it still not compile?

推荐答案

末库：

的gcc -o test.c的测试-lrt

gcc test.c -o test -lrt

链接选项：

-llibrary
-l library
    Search the library named library when linking. 
    (The second alternative with the library as a separate argument
    is only for POSIX compliance and is not recommended.)

    It makes a difference where in the command you write this option;
    the linker searches and processes libraries and object files in the
    order they are specified.
    Thus, `foo.o -lz bar.o' searches library `z' after file foo.o but
    before bar.o. If bar.o refers to functions in `z', those functions
    may not be loaded.

这篇关于未定义的引用'的shm_open“，已经在这里添加-lrt标志的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！