Usage of shell study... tr

Generally, we use tr to replace strings or delete specified strings.

The TR syntax is as follows:

Tr [Option]... set1 [set2]

-C,-C, -- Complement

First complement set1

Replace the characters not in set1 with set2

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

-D, -- delete
Delete characters in set1, do not translate

Delete characters that contain set1:

[[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

Remove duplicate characters and compress them into one character:

[[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

The default value is-T:

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

Other examples:

Case-insensitive replacement:

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