用ldd --version

ldd --version

运行libc.so

你没有看错，libc.so是一个可执行程序。

但前提是你要找到它。因为它并不在PATH所包含的目录下。

pp@dell:~$ ldd `which cat` | grep libc
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0e6fb34000)

pp@dell:~$ /lib/x86_64-linux-gnu/libc.so.6
GNU C Library (Ubuntu GLIBC 2.31-0ubuntu9.9) stable release version 2.31.
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 9.4.0.
libc ABIs: UNIQUE IFUNC ABSOLUTE
For bug reporting instructions, please see:
<https://bugs.launchpad.net/ubuntu/+source/glibc/+bugs>.

用代码获取

main.c

用代码还分了3种方式：

#include <gnu/libc-version.h>
#include <stdio.h>
#include <unistd.h>

int main() {
    // method 1, use macro
    printf("%d.%d\n", __GLIBC__, __GLIBC_MINOR__);

    // method 2, use gnu_get_libc_version 
    puts(gnu_get_libc_version());

    // method 3, use confstr function
    char version[30] = {0};
    confstr(_CS_GNU_LIBC_VERSION, version, 30);
    puts(version);

    return 0;
}

$ gcc main.c -o main
$ ./main
2.30
2.30
glibc 2.30