编译报错无法识别pow、sqrt函数
本帖最后由 baofu007 于 2021-3-3 14:41 编辑源文件中#include <math.h>，然后调用了pow或者其他math函数，编译时加了-lm还是报错，这可能是因为libm和libc两个库的版本不一致。
报错信息如下：
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# gcc exer2.c -lm -o exer2
/lib/x86_64-linux-gnu/libm.so.6: undefined reference to `__strtof128_nan@GLIBC_PRIVATE'
collect2: error: ld returned 1 exit status
比如上面这个报错是/lib/x86_64-linux-gnu/libm.so.6库报的错，可以查看这个库的版本
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# ll /lib/x86_64-linux-gnu/libm.so.6
lrwxrwxrwx 1 root root 12 Dec 30 03:28 /lib/x86_64-linux-gnu/libm.so.6 -> libm-2.27.so
再查看libc库的版本
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# ll /lib/x86_64-linux-gnu/libc*
-rwxr-xr-x 1 root root 1868984 Jun52020 /lib/x86_64-linux-gnu/libc-2.23.so
lrwxrwxrwx 1 root root 14 May 212020 /lib/x86_64-linux-gnu/libcap.so.2 -> libcap.so.2.24
-rw-r--r-- 1 root root 23128 Oct 232015 /lib/x86_64-linux-gnu/libcap.so.2.24
-rw-r--r-- 1 root root190856 Jun52020 /lib/x86_64-linux-gnu/libcidn-2.23.so
lrwxrwxrwx 1 root root 15 Jun52020 /lib/x86_64-linux-gnu/libcidn.so.1 -> libcidn-2.23.so
lrwxrwxrwx 1 root root 17 Jan 222020 /lib/x86_64-linux-gnu/libcom_err.so.2 -> libcom_err.so.2.1
-rw-r--r-- 1 root root 14648 Jan 222020 /lib/x86_64-linux-gnu/libcom_err.so.2.1
-rw-r--r-- 1 root root 39224 Jun52020 /lib/x86_64-linux-gnu/libcrypt-2.23.so
-rw-r--r-- 1 root root 2365984 Sep 15 15:30 /lib/x86_64-linux-gnu/libcrypto.so.1.0.0
lrwxrwxrwx 1 root root 22 Sep62017 /lib/x86_64-linux-gnu/libcryptsetup.so.4 -> libcryptsetup.so.4.6.0
-rw-r--r-- 1 root root158920 Sep62017 /lib/x86_64-linux-gnu/libcryptsetup.so.4.6.0
lrwxrwxrwx 1 root root 16 Jun52020 /lib/x86_64-linux-gnu/libcrypt.so.1 -> libcrypt-2.23.so
lrwxrwxrwx 1 root root 12 Jun52020 /lib/x86_64-linux-gnu/libc.so.6 -> libc-2.23.so
发现libm.so.6连接的libm是2.27版本，libc.so.6连接的libc是2.23版本，版本不一致，可以将libm改为引用2.23版本
1、可以看到有一个libm-2.23.so库存在
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# ll /lib/x86_64-linux-gnu/libm*
-rw-r--r-- 1 root root 1088952 Jun52020 /lib/x86_64-linux-gnu/libm-2.23.so
-rw-r--r-- 1 root root 1700792 Oct 26 09:25 /lib/x86_64-linux-gnu/libm-2.27.so
-rw-r--r-- 1 root root 18776 Jun52020 /lib/x86_64-linux-gnu/libmemusage.so
lrwxrwxrwx 1 root root 15 May 212020 /lib/x86_64-linux-gnu/libmnl.so.0 -> libmnl.so.0.1.0
-rw-r--r-- 1 root root 22520 Aug 282014 /lib/x86_64-linux-gnu/libmnl.so.0.1.0
lrwxrwxrwx 1 root root 17 Jan 272020 /lib/x86_64-linux-gnu/libmount.so.1 -> libmount.so.1.1.0
-rw-r--r-- 1 root root286824 Jan 272020 /lib/x86_64-linux-gnu/libmount.so.1.1.0
lrwxrwxrwx 1 root root 12 Dec 30 03:28 /lib/x86_64-linux-gnu/libm.so.6 -> libm-2.27.so
-rw-r--r-- 1 root root166368 Jun52020 /lib/x86_64-linux-gnu/libmvec-2.23.so
lrwxrwxrwx 1 root root 15 Jun52020 /lib/x86_64-linux-gnu/libmvec.so.1 -> libmvec-2.23.so
2、只需要把libm.so.6连接到libm-2.23.so就可以
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# cd /lib/x86_64-linux-gnu
(base) root@ubuntu:/lib/x86_64-linux-gnu# rm -rf libm.so.6
(base) root@ubuntu:/lib/x86_64-linux-gnu# ln -s libm-2.23.so libm.so.6
3、查看一下是否连接成功，如下连接成功libm.so.6 -> libm-2.23.so
(base) root@ubuntu:/lib/x86_64-linux-gnu# ll /lib/x86_64-linux-gnu/libm*
-rw-r--r-- 1 root root 1088952 Jun52020 /lib/x86_64-linux-gnu/libm-2.23.so
-rw-r--r-- 1 root root 1700792 Oct 26 09:25 /lib/x86_64-linux-gnu/libm-2.27.so
-rw-r--r-- 1 root root 18776 Jun52020 /lib/x86_64-linux-gnu/libmemusage.so
lrwxrwxrwx 1 root root 15 May 212020 /lib/x86_64-linux-gnu/libmnl.so.0 -> libmnl.so.0.1.0
-rw-r--r-- 1 root root 22520 Aug 282014 /lib/x86_64-linux-gnu/libmnl.so.0.1.0
lrwxrwxrwx 1 root root 17 Jan 272020 /lib/x86_64-linux-gnu/libmount.so.1 -> libmount.so.1.1.0
-rw-r--r-- 1 root root286824 Jan 272020 /lib/x86_64-linux-gnu/libmount.so.1.1.0
lrwxrwxrwx 1 root root 12 Mar3 01:22 /lib/x86_64-linux-gnu/libm.so.6 -> libm-2.23.so
-rw-r--r-- 1 root root166368 Jun52020 /lib/x86_64-linux-gnu/libmvec-2.23.so
lrwxrwxrwx 1 root root 15 Jun52020 /lib/x86_64-linux-gnu/libmvec.so.1 -> libmvec-2.23.so
4、问题解决
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# gcc exer2.c -lm -o exer2
(base) root@ubuntu:/home/yongjie/learning/c/s1e15# ./exer2
Number: 1229
页:
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