SHELL STUDY....tr的用法

標籤：linux   shell   tr   

一般我們使用tr來做字串的替換，或者刪除指定的字串

tr的文法如下：

  tr [OPTION]... SET1 [SET2]

       -c, -C, --complement

              first complement SET1

將非SET1中的字元替換為SET2

[[email protected] ~]$ echo "lubinsu" | tr -c "l" "A"lAAAAAAA

       -d, --delete
              delete characters in SET1, do not translate

刪除包含了SET1中的字元：

[[email protected] ~]$ echo "lubinsu" | tr -d "u"lbins

[[email protected] ~]$ echo "lu123b123ins41u" | tr -d "0-9"lubinsu

       -s, --squeeze-repeats              replace  each  input  sequence  of  a  repeated character that is listed in SET1 with a single
              occurrence of that character

去除重複字元，壓縮為一個字元：

[[email protected] ~]$ echo "lubinsu" | tr -c "l\n" "A"lAAAAAA[[email protected] ~]$ echo "lubinsu" | tr -cs "l\n" "A"lA

       -t, --truncate-set1

              first truncate SET1 to length of SET2

預設為-t：

[[email protected] ~]$ echo "lubinsu" | tr -t "lu" "abc"abbinsb[[email protected] ~]$ echo "lubinsu" | tr "lu" "abc"abbinsb

其他樣本：

大小寫替換：

[[email protected] ~]$ echo "lubinsu" | tr "a-z" "A-Z"LUBINSU[[email protected] ~]$ echo "lubinsu" | tr [:lower:] [:upper:]LUBINSU