方法一：
找到libc的DSO(dynamic shared object)并运行它，如下所示：
[whb@jcwkyl ~]$ locate libc.so
/lib/libc.so.6
/lib/i686/nosegneg/libc.so.6
/usr/lib/libc.so
[whb@jcwkyl ~]$ /lib/libc.so.6
GNU C Library stable release version 2.5, by Roland McGrath et al.
Copyright (C) 2006 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 4.1.2 20070626 (Red Hat 4.1.2-14).
Compiled on a Linux 2.6.9 system on 2008-05-23.
Available extensions:
The C stubs add-on version 2.1.2.
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
GNU libio by Per Bothner
NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
RT using linux kernel aio
Thread-local storage support included.
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
方法二：
将下面的C代码编译运行：
- #include <stdio.h>
- #include <gnu/libc-version.h>
- int main (void) { puts (gnu_get_libc_version ()); return 0; }
[whb@jcwkyl c]$ gcc checkglibcversion.c -o checkglibcversion
[whb@jcwkyl c]$ ./checkglibcversion
2.5
