###这里是系统要求\n当前用户（shiyanlou）家目录下的04目录下有一个名为messages的系统日志文件，请您在其中找到和软件更新yum相关的日志提取其中的日期、时间和信息字段，并存储到当前用户（shiyanlou）家目录下的yum_messages文件中，messages样例如下：

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Mar 30 16:33:30 localhost yum[32835]: Installed: apr-1.4.8-3.el7_4.1.x86_64\nMar 30 16:33:30 localhost yum[32835]: Installed: apr-util-1.5.2-6.el7.x86_64\nMar 30 16:33:31 localhost yum[32835]: Installed: httpd-tools-2.4.6-67.el7.centos.6.x86_64\nMar 30 16:33:31 localhost yum[32835]: Installed: mailcap-2.1.41-2.el7.noarch \n

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提取后应为：

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Mar 30 16:33:30 Installed: apr-1.4.8-3.el7_4.1.x86_64\nMar 30 16:33:30 Installed: apr-util-1.5.2-6.el7.x86_64\nMar 30 16:33:31 Installed: httpd-tools-2.4.6-67.el7.centos.6.x86_64\nMar 30 16:33:31 Installed: mailcap-2.1.41-2.el7.noarch\n

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###这里是系统文件筛选后的数据

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shiyanlou:04/ $ grep -r yum messages                                                                            \nMar 30 16:33:30 localhost yum[32835]: Installed: apr-1.4.8-3.el7_4.1.x86_64\nMar 30 16:33:30 localhost yum[32835]: Installed: apr-util-1.5.2-6.el7.x86_64\nMar 30 16:33:31 localhost yum[32835]: Installed: httpd-tools-2.4.6-67.el7.centos.6.x86_64\nMar 30 16:33:31 localhost yum[32835]: Installed: mailcap-2.1.41-2.el7.noarch\nMar 30 16:33:35 localhost yum[32835]: Installed: httpd-2.4.6-67.el7.centos.6.x86_64\nMar 30 16:33:48 localhost yum[32927]: Installed: vsftpd-3.0.2-22.el7.x86_64\n

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####然后这是我提取的文件

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shiyanlou:04/ $ cat /home/shiyanlou/yum_message                                                                 \nMar 30 16:33:30 Installed: apr-1.4.8-3.el7_4.1.x86_64\nMar 30 16:33:30 Installed: apr-util-1.5.2-6.el7.x86_64\nMar 30 16:33:31 Installed: httpd-tools-2.4.6-67.el7.centos.6.x86_64\nMar 30 16:33:31 Installed: mailcap-2.1.41-2.el7.noarch\nMar 30 16:33:35 Installed: httpd-2.4.6-67.el7.centos.6.x86_64\nMar 30 16:33:48 Installed: vsftpd-3.0.2-22.el7.x86_64\n

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我真看不懂我那出错了

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