在执行 php -i |grep redis 时显示以下报错信息（但在phpinfo查看时一切正常）：
MIB search path: /root/.snmp/mibs:/usr/share/snmp/mibs:/usr/share/snmp/mibs/iana:/usr/share/snmp/mibs/ietf:/usr/share/mibs/site:/usr/share/snmp/mibs:/usr/share/mibs/iana:/usr/share/mibs/ietf:/usr/share/mibs/netsnmp Cannot find module (SNMPv2-TC): At line 10 in /usr/share/snmp/mibs/UCD-DLMOD-MIB.txt Cannot find module (SNMPv2-SMI): At line 34 in /usr/share/snmp/mibs/UCD-SNMP-MIB.txt Cannot find module (SNMPv2-TC): At line 37 in /usr/share/snmp/mibs/UCD-SNMP-MIB.txt Did not find 'enterprises' in module #-1 (/usr/share/snmp/mibs/UCD-SNMP-MIB.txt) Did not find 'DisplayString' in module #-1 (/usr/share/snmp/mibs/UCD-SNMP-MIB.txt) Did not find 'TruthValue' in module #-1 (/usr/share/snmp/mibs/UCD-SNMP-MIB.txt)
....
在网上好多有建议直接执行 sudo apt-get remove php5-snmp 删掉该扩展来解决的。
但，我是需要此扩展的啊。。。
这个问题时因为我们安装时执行 apt-get install php5-snmp ，少了php5-snmp必要的snmp,所以执行下面操作来安装扩展搞定！
sudo apt-get install snmp
Done！
参考：http://qaru.site/questions/75652/ubuntu-typing-php-in-terminal-shows-a-lot-of-errors