php做网站实例,电子商务网站设计说明,青山做网站,阿里云建网站流程正则表达式是一种字符模式#xff0c;用于在查找过程中匹配制定的字符。元字符通常在Linux中分为两类#xff1a;Shell元字符#xff0c;由Linux Shell进行解析#xff1b;正则表达式元字符#xff0c;由vi/grep/sed/awk等文本处理工具进行解析#xff1b;正则表达式一般…正则表达式是一种字符模式用于在查找过程中匹配制定的字符。元字符通常在Linux中分为两类Shell元字符由Linux Shell进行解析正则表达式元字符由vi/grep/sed/awk等文本处理工具进行解析正则表达式一般以文本行进行处理在进行下面实例之前先为grep命令设置—color参数$ alias grepgrep --colorauto 这样每次过滤出来的字符串都会带色彩了。在开始之前还需要做一件事情就是创建一个测试用的re-file文件内容如下$ cat re-file I had a lovely time on our little picnic. Lovers were all around us. It is springtime. Oh love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. is forever. I live for you. Its hard to get back in the groove. 正则表达式元字符特殊的元字符扩展的正则表达式实操匹配以love开头的所有行$ grep ^love re-file love, how much I adore you. Do you know 匹配love结尾的所有行$ grep love$ re-file clover. Did you see them? I can only hope love. 匹配以l开头中间包含两个字符结尾是e的所有行$ grep l..e re-file I had a lovely time on our little picnic. love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. is forever. I live for you. Its hard to get back in the 匹配0个或多个空行后面是love的字符$ grep *love re-file I had a lovely time on our little picnic. love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. 匹配love或Love$ grep [Ll]ove re-file # 对l不区分大小写 I had a lovely time on our little picnic. Lovers were all around us. It is springtime. Oh love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. 匹配A-Z的字母其次是ove$ grep [A-Z]ove re-file Lovers were all around us. It is springtime. Oh 匹配不在A-Z范围内的任何字符行所有的小写字符$ grep [^A-Z] re-file I had a lovely time on our little picnic. Lovers were all around us. It is springtime. Oh love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. is forever. I live for you. Its hard to get back in the groove. 匹配love.$ grep love. re-file clover. Did you see them? I can only hope love. 匹配空格$ grep ^$ re-file 匹配任意字符$ grep .* re-file I had a lovely time on our little picnic. Lovers were all around us. It is springtime. Oh love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. is forever. I live for you. Its hard to get back in the groove. 前面o字符重复2到4次$ grep o{2,4} re-file groove. 重复o字符至少2次$ grep o{2,} re-file groove. 重复0字符最多2次$ grep o{,2} re-file I had a lovely time on our little picnic. Lovers were all around us. It is springtime. Oh love, how much I adore you. Do you know the extent of my love? Oh, by the way, I think I lost my gloves somewhere out in that field of clover. Did you see them? I can only hope love. is forever. I live for you. Its hard to get back in the groove. 重复前一个字符一个或一个以$ egrep god linux.txt Linux is a good god assdxw bcvnbvbjk gooodfs awrerdxxhkl good 0个或者一个字符anshengUbuntu:/tmp$ egrep go?d linux.txt god assdxw bcvnbvbjk gdsystem awxxxx 或查找多个字符串$ egrep gd|good linux.txt Linux is a good gdsystem awxxxx good 分组过滤匹配$ egrep g(la|oo)d linux.txt Linux is a good glad good 感谢支持后台私信《Linux》获取C/Linux后台开发进阶视频资料。
