Linux之tr命令

[root@BASE ~]# cat c.txt   
aa
        
    ccc
bbb    bbbb
[root@BASE ~]# cat c.txt|tr -s " "            //删除连续重复的空格只保留一个
aa
 
 ccc
bbb bbbb
[root@BASE ~]# cat c.txt|tr -s " ","a","c","b"           //删除重复的空格，a，b，c只保留一个

a
 
 c
b b
[root@BASE ~]# cat c.txt|tr -s " " "k"         //删除重复的空格只保留一个，并且将空格替换成“k”
aa
k
kccc
bbbkbbbb
[root@BASE ~]# cat c.txt|tr -d " "           //删除空格
aa

ccc
bbbbbbb
[root@BASE ~]# cat c.txt|tr -d "aaa"         

        
    ccc
bbb    bbbb
[root@BASE ~]# cat c.txt|tr -d "a"  

        
    ccc
bbb    bbbb
[root@BASE ~]#