@H_404_0@.:任意单个字符 @H_404_0@[]:指定范围内的任意单个字符 @H_404_0@[^]:指定范围外的任意单个字符 @H_404_0@次数匹配 @H_404_0@*:匹配其前字符任意次 @H_404_0@?:匹配其前字符0次或1次,不需要加反钭线\ @H_404_0@+:匹配其前字符至少一次,相当于\{1,\}(?+组合相当于*) @H_404_0@{m,n}:匹配其前字符至少m次至多n次,不需要加反钭线\ @H_404_0@位置锚定 @H_404_0@^ CHARE:行首锚定 @H_404_0@CHARE $:行尾锚定 @H_404_0@\< CHARE:词首锚定
@H_404_0@CHARE \>:词尾锚定 @H_404_0@分组: @H_404_0@():不需要加反钭线\,后向引用\1,\2,\3...... @H_404_0@或者
@H_404_0@|:表示or,其匹配的是坚线前面和后面的整体部分 @H_404_0@如:文件内容如下 @H_502_45@[root@station01~]#cattest5.txt b bag banana Back @H_404_0@执行结果:
@H_502_45@[root@station01~]#grep--color-E'b|bag'test5.txt b bag banana @H_404_0@即匹配的只是b和bag @H_502_45@[root@station01~]#cattest5.txt b bag banana Back Bag
执行结果如下:
@H_502_45@[root@station01~]#grep--color-E'(B|b)ag'test5.txt bag Bag@H_404_0@如找出/boot/grub/grub.conf文件中至少一个空白字符开头的行 @H_404_0@执行结果如下: @H_502_45@[root@station01~]#grep-E'^[[:space:]]+'/boot/grub/grub.conf root(hd0,0) kernel/vmlinuz-2.6.32-71.el6.i686roroot=/ @H_404_0@如: @H_404_0@找出/boot/grub/grub.conf文件中1-255之间的数字 @H_404_0@执行结果如下: @H_502_45@[root@station01~]#grep--color-E'\<([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>'/boot/grub/grub.conf timeout=5 titleRedHatEnterpriseLinux(2.6.32-71.el6.i686) kernel/vmlinuz-2.6.32-71.el6.i686roroot=/dev/mapper/vg_station01-lv_rootrd_LVM_LV=vg_station01/lv_rootrd_LVM_LV=vg_station01/lv_swaprd_NO_LUKSrd_NO_MDrd_NO_DMLANG=en_US.UTF-8SYSFONT=latarcyrheb-sun16KEYBOARDTYPE=pcKEYTABLE=uscrashkernel=autorhgbquiet initrd/initramfs-2.6.32-71.el6.i686.img @H_404_0@找出ifconfig文件中1-255的数字
@H_404_0@执行结果如下: @H_502_45@[root@station01~]#ifconfig|grep--color-E'\<([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>' eth0Linkencap:EthernetHWaddr00:0C:29:52:C5:1B inetaddr:172.24.5.56Bcast:172.24.5.255Mask:255.255.255.0 inet6addr:fe80::20c:29ff:fe52:c51b/64Scope:Link UPBROADCASTRUNNINGMULTICASTMTU:1500Metric:1 RXbytes:1793759242(1.6GiB)TXbytes:4462480(4.2MiB) Interrupt:19Baseaddress:0x2000 inetaddr:127.0.0.1Mask:255.0.0.0 inet6addr:::1/128Scope:Host UPLOOPBACKRUNNINGMTU:16436Metric:1 RXbytes:76440(74.6KiB)TXbytes:76440(74.6KiB) @H_404_0@找出ifconfig文件中点分十进制的类似ip地址的数字
@H_404_0@执行结果如下: @H_404_0@1) @H_502_45@[root@station01~]#ifconfig|egrep-o'\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>' 172.24.5.56 172.24.5.255 255.255.255.0 127.0.0.1 255.0.0.0 @H_404_0@2)
[root@station01~]#ifconfig|egrep--color'\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>' inetaddr:172.24.5.56Bcast:172.24.5.255Mask:255.255.255.0 inetaddr:127.0.0.1Mask:255.0.0.0@H_404_0@3)次数匹配 @H_502_45@[root@station01~]#ifconfig|egrep--color'(\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>\.){3}\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>' inetaddr:172.24.5.56Bcast:172.24.5.255Mask:255.255.255.0 inetaddr:127.0.0.1Mask:255.0.0.0 @H_404_0@4) @H_404_0@找出ifconfig文件中A类(1-127)、B类(128-191)、C类(192-223)IP地址 @H_502_45@[root@station01~]#ifconfig|egrep--color'\<([1-9]|[1-9][0-9]|1[0-9][0-9]|2[01][0-9]|22[0-3])\>(\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])\>){2}\.\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])\>' inetaddr:172.24.5.56Bcast:172.24.5.255Mask:255.255.255.0 inetaddr:127.0.0.1Mask:255.0.0.0 @H_404_0@2015年2朋18日 @H_404_0@GB-2312