I have a server running CentOS 6 successfully upgraded to CentOS 7.

The only problem I encountered so far is that ‘grep’ doesn’t work.

[root@zilla ~]# grep
grep: error while loading shared libraries: libpcre.so.0: cannot open shared object file: No such file or directory
[root@zilla ~]# ldd /usr/bin/grep
        linux-vdso.so.1 =>  (0x00007ffc0b639000)
        libpcre.so.0 => not found
        libc.so.6 => /lib64/libc.so.6 (0x00007f6be1c6c000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f6be2038000)

First thing I tried was to reinstall pcre package which provides libpcre.so*. It still didn’t work. Fortunately, someone has posted a solution as the following:

[root@zilla ~]# link /usr/lib64/libpcre.so.1 /lib64/libpcre.so.0
[root@zilla ~]# grep --version
grep (GNU grep) 2.20
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Mike Haertel and others, see <http://git.sv.gnu.org/cgit/grep.git/tree/AUTHORS>.

Credit: update to Centos 7; libpcre.so.0 No such file or directory