The easiest way is to use ldd which comes with glibc
Just run this command ldd --version :
[email protected]:~$ ldd --version
ldd (Ubuntu GLIBC 2.23-0ubuntu9) 2.23
Copyright (C) 2016 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.
Written by Roland McGrath and Ulrich Drepper.
Their is two additional ways to find out the glibc version:
-
Check the version of the installed glibc rpm package : this by runing this command
rpm -q glibc -
Check the version of the used libc.so file. This way is a little bit more difficult. You can check it in this link: Linux: Check the glibc version
even easier
use ldd –version
This should return the glibc version being used i.e.
$ ldd --version
ldd (GNU libc) 2.17
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
…
which is the same result as running my libc library
$ /lib/libc.so.6
GNU C Library (GNU libc) stable release version 2.17, by Roland McGrath et al.
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
…
gnu_get_libc_version identifies the runtime version of the GNU C Library.
If what you care about is the compile-time version (that is, the version that provided the headers in /usr/include), you should look at the macros __GLIBC__ and __GLIBC_MINOR__. These expand to positive integers, and will be defined as a side-effect of including any header file provided by the GNU C Library; this means you can include a standard header, and then use #ifdef __GLIBC__ to decide whether you can include a nonstandard header like gnu/libc-version.h.
Expanding the test program from the accepted answer:
#include <stdio.h>
#ifdef __GLIBC__
#include <gnu/libc-version.h>
#endif
int
main(void)
{
#ifdef __GLIBC__
printf("GNU libc compile-time version: %u.%un", __GLIBC__, __GLIBC_MINOR__);
printf("GNU libc runtime version: %sn", gnu_get_libc_version());
return 0;
#else
puts("Not the GNU C Library");
return 1;
#endif
}
When I compile and run this program on the computer I’m typing this answer on (which is a Mac) it prints
Not the GNU C Library
but when compiled and run on a nearby Linux box it prints
GNU libc compile-time version: 2.24
GNU libc runtime version: 2.24
Under normal circumstances, the “runtime” version could be bigger than the “compile-time” version, but never smaller. The major version number is unlikely ever to change again (the last time it changed was the “libc6 transition” in 1997).
If you would prefer a shell ‘one-liner’ to dump these macros, use:
echo '#include <errno.h>' | gcc -xc - -E -dM |
grep -E '^#define __GLIBC(|_MINOR)__ ' | sort
The grep pattern is chosen to match only the two macros that are relevant, because there are dozens of internal macros named __GLIBC_somethingorother that you don’t want to have to read through.
Use -print-file-name gcc option:
$ gcc -print-file-name=libc.so
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/libc.so
That gives the path. Now:
$ file /usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/libc.so
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/libc.so: ASCII C program text
$ cat /usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/libc.so
/* GNU ld script
Use the shared library, but some functions are only in
the static library, so try that secondarily. */
OUTPUT_FORMAT(elf64-x86-64)
GROUP ( /lib64/libc.so.6 /usr/lib64/libc_nonshared.a AS_NEEDED ( /lib64/ld-linux-x86-64.so.2 ) )
Looks like a linker script. libc is special on Linux in that it can be executed:
$ /lib64/libc.so.6
GNU C Library stable release version 2.13, by Roland McGrath et al.
Copyright (C) 2011 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 4.5.1 20100924 (Red Hat 4.5.1-4).
Compiled on a Linux 2.6.35 system on 2011-08-05.
Available extensions:
Support for some architectures added on, not maintained in glibc core.
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
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
RT using linux kernel aio
libc ABIs: UNIQUE IFUNC
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
Write a test program (name it for example glibc-version.c):
#include <stdio.h>
#include <stdlib.h>
#include <gnu/libc-version.h>
int main(int argc, char *argv[]) {
printf("GNU libc version: %sn", gnu_get_libc_version());
exit(EXIT_SUCCESS);
}
and compile it with the gcc-4.4 compiler:
gcc-4.4 glibc-version.c -o glibc-version
When you execute ./glibc-version the used glibc version is shown.