awk: Pattern scanning and processing language
August 12th, 2024 12:36 PM Mr. Q Categories: Command
The tr command is used to translate or delete characters from input data. It’s commonly used for tasks such as changing character case, replacing specific characters, or deleting unwanted characters.
Basic Syntax
tr [options] SET1 [SET2]Options
-d: Delete characters specified inSET1.-s: Squeeze multiple adjacent occurrences of characters inSET1into a single occurrence.-c: Complement the set of characters inSET1.
Examples
1. Convert Lowercase to Uppercase
Command:
echo "hello world" | tr 'a-z' 'A-Z'Sample Input:
hello worldSample Output:
HELLO WORLDExplanation:
'a-z'specifies the range of characters to convert from lowercase.'A-Z'specifies the range of characters to convert to uppercase.
2. Delete Specific Characters
Command:
echo "hello 123" | tr -d '0-9'Sample Input:
hello 123Sample Output:
hello Explanation:
-d '0-9'deletes all digits from the input.
3. Squeeze Multiple Spaces into a Single Space
Command:
echo "hello world" | tr -s ' 'Sample Input:
hello worldSample Output:
hello worldExplanation:
-s ' 'squeezes multiple spaces into a single space.
4. Complement Character Set
Command:
echo "hello world" | tr -c 'a-z ' 'X'Sample Input:
hello worldSample Output:
XXXXX XXXXXExplanation:
-c 'a-z 'complements the set of characters specified, replacing everything not in the set withX.
Summary
The tr command is a versatile tool for transforming or deleting characters from text input. It’s useful for tasks like case conversion, character replacement, and formatting text by removing unwanted characters or squeezing repetitions.