How do you use sed to replace the second occurrence in a file?

How do you use sed to replace the second occurrence in a file?

1. Replacing or substituting string : Sed command is mostly used to replace the text in a file.
2. Replacing the nth occurrence of a pattern in a line : Use the /1, /2 etc flags to replace the first, second occurrence of a pattern in a line.

How do I change the last occurrence of a string in Unix?

The following `sed` command will replace the last digit that exists in the string value by the value by double zero (0 0).

How do you grep last occurrence?

6 Answers

1. Print last occurence of x (regex): grep x file | tail -1.
2. Alternatively: tac file | grep -m1 x.
3. Print file from first matching line to end: awk ‘/x/{flag = 1}; flag’ file.
4. Print file from last matching line to end (prints all lines in case of no match): tac file | awk ‘! flag; /x/{flag = 1};’ | tac.

How does SED search and replace last occurrence?

The grep command finds all the occureences and tail selects the last line and sed makes the replacement. sed is trying to get the biggest content in search pattern, so by default form start to the last |00001148| is the biggest pattern available (if any) tac inverts your file. The sed command replaces the first occurrance.

How to replace the last occurrence in a file?

The last occurrence that exists in the 7 th line of the file has been replaced by the word ‘July ‘ in the output. `tac` command is used to reverse the content of the file. `tac` command is used with the `sed` command in the following command to replace the last occurrence of ‘2019 ‘ with the word, ‘2017’.

Which is the substitute command for find and replace?

The s is the substitute command of sed for find and replace It tells sed to find all occurrences of ‘old-text’ and replace with ‘new-text’ in a file named input.txt Verify that file has been updated: Let us see syntax and usage in details.

How to find and replace text in files in Linux?

The procedure to change the text in files under Linux/Unix using sed: Use Stream EDitor (sed) as follows: The s is the substitute command of sed for find and replace It tells sed to find all occurrences of ‘old-text’ and replace with ‘new-text’ in a file named input.txt