glibc学习笔记

1. linux下有很多的C标准库， 如uclibc,klibc， gnu libc是如今使用最广泛的，并且成为了linux的标准C库，原来的libc渐渐不再被维护

2. 查看当前系统glibc版本的两种方法

[root@master ~]# /lib64/libc.so.6 
GNU C Library stable release version 2.12, by Roland McGrath et al.
Copyright (C) 2010 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 4.4.7 20120313 (Red Hat 4.4.7-17).
Compiled on a Linux 2.6.32 system on 2016-05-10.
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
    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>.
[root@master ~]# 

[root@master ~]# ldd --version
ldd (GNU libc) 2.12
Copyright (C) 2010 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.