[shell基礎]——tr命令

Jelly_lyj發表於2017-03-18

(1) tr 字元替換

測試文字內容
# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 loalhost localhost.localdomain localhost6 localhost6.localdomain6

 

把小寫字母替換成大寫字母
# tr "[a-z]" "[A-Z]" < /etc/hosts
127.0.0.1 LOCALHOST LOCALHOST.LOCALDOMAIN LOCALHOST4 LOCALHOST4.LOCALDOMAIN4
::1 LOALHOST LOCALHOST.LOCALDOMAIN LOCALHOST6 LOCALHOST6.LOCALDOMAIN6

 

把：替換成空格
# tr ":" " " < /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
1 loalhost localhost.localdomain localhost6 localhost6.localdomain6

 

注意這種是3-a、4-b、5-c的一一對應替換方式
# echo 112233445566 | tr "345" "abc"
1122aabbcc66

 



(2) -s 將連續相同的字元壓縮成1個字元 

# echo 1122333444555 | tr -s "3"
11223444555

# echo 1122333444555 | tr -s "12345"
12345

去除空行
# cat 1.txt | tr -s "[\n]"

 


(3) tr -s " " " " 替換且壓縮

# cat 5.txt
root tty1 2016-05-22 18:11 (:0)

把空格替換成換行符，並且壓縮了(因為原本中間是有多個空格的)
# tr -s " " "\n" <5.txt
root
tty1
2016-05-22
18:11
(:0)

對比一下不壓縮的情況
# tr " " "\n" <5.txt
root


tty1


2016-05-22
18:11
(:0)

 


(4) -d 刪除

# cat 1.txt
123And the cowwwwwssssss went homeeeeeeeee
456i havvvvve
789theyyyyyyyyy

刪除所有字母
# tr -d "A-z" < 1.txt
123
456
789

tr支援刪除 \n\t等字元
# cat 1.txt | tr -d "\n"
And the cowwwwwssssss went homeeeeeeeeei havvvvve theyyyyyyyyy[root@sxjy rh7]#

刪除“And”字元
# tr -d [And] < 1.txt
123 the cowwwwwssssss wet homeeeeeeeee
456i havvvvve
789theyyyyyyyyy

刪除轉換控制字元：
^的八進位制程式碼是136，^M是015，tab鍵是011，^Z是032
# cat 1.txt | tr -d '[\011\015]'

 

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