# cat /proc/version
Linux version 2.6.18-348.el5 (mockbuild@x86-002.build.bos.redhat.com) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-54)) #1 SMP Wed Nov
详细解释：
The GNU Compiler Collection (GCC) is a compiler system produced by the GNU Project supporting various programming languages.
GNU is a recursive acronym meaning "GNU's not Unix".
A symmetric multiprocessor system (SMP) is a multiprocessor system with centralized shared memory called main memory (MM) operating under a single operating system with two or more homogeneous processors—i.e., it is not a heterogeneous computing system.
# cat /etc/issue
[root@INTG ~]# cat /etc/issue CentOS release 6.5 (Final) Kernel on an m
#cat /etc/redhat-release
CentOS Linux release 7.3.1611 (Core)