错误信息：
ftp: error while loading shared libraries: libreadline.so.5: cannot open shared object file: No such file or directory
解决办法：
yum install -y readline-devel readline
[root@zdx118106 ~]# cd /usr/lib64/
[root@zdx118106 lib64]# ll *libreadline*
lrwxrwxrwx. 1 root root 28 Jul 18 10:13 libreadline.so -> ../../lib64/libreadline.so.6
[root@zdx118106 lib64]# ln -s ../../lib64/libre
libreadline.so.6 libreadline.so.6.0 libresolv-2.12.so libresolv.so.2
[root@zdx118106 lib64]# ln -s ../../lib64/libreadline.so.6 libreadline.so.5
[root@zdx118106 lib64]# ll *libreadline*
lrwxrwxrwx. 1 root root 28 Jul 18 10:13 libreadline.so -> ../../lib64/libreadline.so.6
lrwxrwxrwx. 1 root root 28 Jul 18 10:15 libreadline.so.5 -> ../../lib64/libreadline.so.6
