1、求每班总成绩和平均成绩
[root@Centos7 bin]# awk '!/^name/{a[$2]++;b[$2]+=$3}END{for(i in a){print i,b[i],b[i]/a[i]}}' f1 4 100 50 5 40 40 6 50 50 1 430 71.6667 2 210 70 3 450 56.25
[root@Centos7 bin]# cat f1 name class score A 1 100 B 2 90 C 3 80 D 1 70 C 3 80 D 1 70 C 3 80 D 1 70 E 2 60 F 3 50 G 1 40 H 4 30 I 5 40 I 3 40 I 3 40 I 3 40 J 6 50 I 3 40 K 2 60 L 4 70 M 1 80
2、为编译安装的httpd服务,实现service unit文件
(1)安装编译环境:
① yum install -y pcre
② yum install -y pcre-devel
③ yum groupinstall -y "Development tools"
(2)下载源码包:
① apr-1.5.0.tar.bz2
② apr-util-1.5.2.tar.bz2
③ httpd-2.4.9.tar.bz2
(3)安装依赖的源码包,先安装apr,在安装apr-util,因为apr-util是apr的工具,apr-util会依赖apr的存在,(如apr未安装,则会提示用此参数指定apr的安装地址 – – with-apr=/usr/local/apr)
①安装apr
./configure –prefix=/usr/local/apr
make && make install
②.安装apr-util
./configure –prefix=/usr/local/apr-util –with-apr=/usr/local/apr
make && make install
③.安装httpd
./configure –prefix=/usr/local/httpd –sysconfdir=/etc/httpd –enable-so –enable–ssl –enable-cgi –enable-rewrite –with-zlib –with-pcre –with-apr=/usr/local/apr –with-apr-util=/usr/local/apr-util –enable-modeles=most –enable-mpms-shared=all –with-mpm=event
make && make install
(4)完成http安装后的操作
①添加二进制程序文件地址到/etc/profile.d/httpd.sh文件中
[root@Centos7 local]# vim /etc/profile.d/httpd.sh export PATH=$PATH:/usr/local/httpd/bin //添加此行
②添加man文档路径到man配置文件中:
[root@Centos7 local]# vim /etc/man_db.conf MANDATORY_MANPATH /usr/local/httpd/man //添加此行
③添加httpd头文件的软链接到/usr/include目录下
[root@Centos7 local]# ln -sv /usr/local/httpd/include/ /usr/include/httpd
(5)编辑httpd.service unit文件
[root@Centos7 ~]# vim /etc/systemd/system/httpd.service [Unit] Description=The Apache HTTP Server After=network.target remote-fs.target nss-lookup.target Documentation=man:httpd(8) Documentation=man:apachectl(8) [Service] Type=notify EnvironmentFile=/etc/sysconfig/httpd ExecStart=/usr/sbin/httpd $OPTIONS -DFOREGROUND ExecReload=/usr/sbin/httpd $OPTIONS -k graceful ExecStop=/bin/kill -WINCH ${MAINPID} KillSignal=SIGCONT PrivateTmp=true [Install] WantedBy=multi-user.target
3、破解centos7 口令
(1)在启动时选择内核按e键进入编辑模式
(2)在以linux16开头的行的行尾添加内核参数:rd.break
(3)按ctrl + x 键启动进入系统
(4)将根文件系统重新挂载为可读可写:mount -o remount,rw /sysroot
(5)切换到根文件系统:chroot /sysroot
(6)更改密码: passwd
(7)创建重新打标签的文件,让系统重新打标签:touch /.autorelabel
(8)退出重启系统更改完成:exit
4、修改默认的启动内核
(1)修改grub配置文件:将GRUB_DEFAULT项更改为需要启动的内核次序(我这里指定为0,表示/boot/grub2/grub.cfg文件中第一个内核)
[root@Centos7 bin]# vim /etc/default/grub GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=0 GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet" GRUB_DISABLE_RECOVERY="true"
(2)可查看/boot/grub2/grub.cfg文件中的内核次序:
menuentry 'CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-327.el7.x86_64-advanced-657cf10a-8a36-43e2-aec5-aa4fc1596776' //menuentry 开头的为内核启动次序
(3)重新生成配置grub配置文件
[root@Centos7 bin]# grub2-mkconfig -o /etc/grub2.cfg Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.10.0-327.el7.x86_64 Found initrd image: /boot/initramfs-3.10.0-327.el7.x86_64.img Found linux image: /boot/vmlinuz-0-rescue-589c15d91a5b4e7dba045eb00363a558 Found initrd image: /boot/initramfs-0-rescue-589c15d91a5b4e7dba045eb00363a558.img done 注:/etc/grub2.cfg文件为/boot/grub2/grub.cfg文件的软链接,使用其中一个都可以
5、启动时临时禁用SELinux
(1)在内核菜单中编辑内核参数,在linux16开头的行的行尾添加内核参数:selinux=0,按ctrl + x 键进入系统,
[root@Centos7 ~]# getenforce //添加内核参数完毕后进入系统查看selinux值 Disabled
[root@Centos7 ~]# cat /etc/selinux/config # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. SELINUX=enforcing //文件并没有发生改变,下次重启即为开启selinux
6、启动时进入emergency模式
(1)在启动时添加内核参数,只对当前本次启动生效,下次重启不生效,按ctrl + x键进入系统
7、删除编译安装的新内核
(1)删除/boot/目录下包括3.18字样的内核文件
[root@Centos7 /]# rm -f /boot/*3.18*
(2)删除/boot/grub2/grub.cfg文件中的启动内核项
(3)删除/lib/modules目录下的内核模块文件:
[root@Centos7 ~]# rm -rf /lib/modules/3.18.41-SuperDream.ux
(4)删除原来解压内核文件到的目录下的文件:
[root@Centos7 ~]# rm -rf /usr/src/3.18.41
(5)重启
原创文章,作者:Lii,如若转载,请注明出处:http://www.178linux.com/47934
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