問題：SSH登錄centos7系統後不停的刷日誌，輸入命令不生效
問題原因：配置了/etc/profile文件，文件中錯誤配置導致的。如我在文件末尾添加了source /etc/profile 引起了本次問題。
注意：系統級別環境變量謹慎修改
修復辦法：進入單用戶模式，修改profile文件。
錯誤日誌：
-bash: /usr/bin/id: Argument list too long
-bash: [: : integer expression expected
-bash: /usr/bin/awk: Argument list too long
-bash: /usr/bin/sed: Argument list too long
-bash: /usr/bin/whoami: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/libexec/grepconf.sh: Argument list too long
-bash: /usr/bin/tty: Argument list too long
-bash: /usr/bin/awk: Argument list too long
-bash: /usr/bin/who: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/libexec/grepconf.sh: Argument list too long
-bash: /usr/bin/tty: Argument list too long
-bash: /usr/bin/who: Argument list too long
-bash: /usr/bin/awk: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: [: : integer expression expected
-bash: /usr/bin/sed: Argument list too long
-bash: /usr/bin/awk: Argument list too long
-bash: /usr/bin/whoami: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/libexec/grepconf.sh: Argument list too long
-bash: /usr/bin/tty: Argument list too long
-bash: /usr/bin/who: Argument list too long
-bash: /usr/bin/awk: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: [: : integer expression expected
-bash: /usr/bin/awk: Argument list too long
-bash: /usr/bin/sed: Argument list too long
-bash: /usr/bin/whoami: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/bin/id: Argument list too long
-bash: /usr/libexec/grepconf.sh: Argument list too long