tr命令
从标准输入中替换、缩减或删除字符，并将结果写到标准输出。
tr [option] [SET1] [SET2]
tr [选项] [字符1] [字符2]
-d 删除字符
-s 保留连续字符的第一个字符，删除其他字符
-c 使用第一个字符率（set1）的补集，取反
[root@cs6 ~]# cat lewen.txt I am lewen student! I love linux. I like badminton ball,billiard ball and chinese chess! my blog is http://lewen.blog.51cto.com our site is http://www.wenyule.top my qq num is 846009315 not 8460009315 my god,i am not oldboy, but lewen!
将文件中出现的“abc”替换为“xyz”
[root@cs6 ~]# tr 'abc' 'xyz' <lewen.txt #<== tr命令接文件比较特殊，需要输入重定向符号“<”。 I xm lewen student! I love linux. I like yxdminton yxll,yillixrd yxll xnd zhinese zhess! my ylog is http://lewen.ylog.51zto.zom our site is http://www.wenyule.top my qq num is 846009315 not 8460009315 my god,i xm not oldyoy, yut lewen! 凡是在文本中出现的“a”均应转换成“x”，“b”均应转换成“y”，“c”均应转换成“z”，而不是仅仅将字符串“abc”替换为字符串“xyz”。
使用tr命令“统一”字母大小写
[root@cs6 ~]# tr '[a-z]' '[A-Z]' <lewen.txt I AM LEWEN STUDENT! I LOVE LINUX. I LIKE BADMINTON BALL,BILLIARD BALL AND CHINESE CHESS! MY BLOG IS HTTP://LEWEN.BLOG.51CTO.COM OUR SITE IS HTTP://WWW.WENYULE.TOP MY QQ NUM IS 846009315 NOT 8460009315 MY GOD,I AM NOT OLDBOY, BUT LEWEN!
将数字0-9替换为a-j
[root@cs6 ~]# tr '[0-9]' '[a-j]' <lewen.txt I am lewen student! I love linux. I like badminton ball,billiard ball and chinese chess! my blog is http://lewen.blog.fbcto.com our site is http://www.wenyule.top my qq num is iegaajdbf not iegaaajdbf my god,i am not oldboy, but lewen!
删除文件中出现的lewen中的每个字符
[root@cs6 ~]# tr -d 'lewen' <lewen.txt I am studt! I ov iux. I ik badmito ba,biiard ba ad chis chss! my bog is http://.bog.51cto.com our sit is http://.yu.top my qq um is 846009315 ot 8460009315 my god,i am ot odboy, but !
删除文件中出现的换行"
",制表," " 字符
[root@cs6 ~]# tr -d ' ' < lewen.txt I am lewen student!I love linux.I like badminton ball,billiard ball and chinese chess!my blog is http://lewen.blog.51cto.comour site is http://www.wenyule.topmy qq num is 846009315not 8460009315my god,i am not oldboy, but lewen![root@cs6 ~]#
删除连续字符（-s）的例子
[root@cs6 ~]# echo 'llllleeeewwwweennn'|tr -s lewen #<==使用-s参数将连续的字符压缩成一个。 lewen
取反功能（-c）的例子
[root@cs6 ~]# tr '0-9' '*' <lewen.txt I am lewen student! I love linux. I like badminton ball,billiard ball and chinese chess! my blog is http://lewen.blog.**cto.com our site is http://www.wenyule.top my qq num is ********* not ********** my god,i am not oldboy, but lewen! [root@cs6 ~]# tr -c '0-9' '*' <lewen.txt #<==使用参数-c，除了数字，其他的字符包括换行符都会替换为*。 ***********************************************************************************************************************51********************************************************846009315******8460009315************************************[root@cs6 ~]#