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Tag: grep

Filter followed tail to file using grep and redirect

I want to get the output of tail -f /var/log/apache2/error.log | grep “trace1” into a file. But tail -f /var/log/apache2/error.log | grep “trace1” > output.txt does not work, while the first command gives an output in my terminal window as expected. I guess it has to do with the follow-parameter, because if I omit the “-f”, the output file is

linux replace string in files recursively

I have a folder which is full of *.java files. it has the following method in it: i wanted to change this as following: I have searched in the forum and found some solutions, replce string is what i wanted so tried the following: But it throwing me the following error: I guess the old_string and new_string formates are the

using only ‘grep’ command to get specific column

This below shows this some lines of csv file, i want to get the results that only get the Population column with only using grep command. results i want: The command i made for this problem was which got results below how can i get rid of the rest of things without using awk sed or any other things? Answer

Replacing line of text cointing using sed

I’m trying to replace document.querySelector(‘.popup’).classList.add(‘active’) by document.querySelector(‘.popup’).classList.add(‘noactive’) Answer You can use See the online demo. The regex is POSIX BRE compliant and matches (document.querySelector(‘.popup’).classList.add(‘) – Group 1 (1): a literal document.querySelector(‘.popup’).classList.add(‘ text (active’)) – Group 2 (2): a literal active’) text. Note the capturing groups in a POSIX BRE regex are set with (…). The literal dots need escaping and

grep to read exact data from text file

I have file test1.txt file, i am trying to read variable which is enclosed in double quotes and starting with hyphen for eg: “-color”. i trying to use this grep command cat test1.txt | grep getParm | sed ‘s/getParm(/ /;s/&/ /;s/,/ /;s/”/ /g’ | awk ‘{print $3}’ , where i am not able to read exact data for all variables

How to find the lines that include same two letters by using grep?

For example “Conclusion” has two c but at different index. I am using It shows me only like “Accept”. I mean it shows me only these words are with side by side but i want to see here also “Conclusion” Answer If you plan to match lines that contain any two identical letters that are not necessarily consecutive, you can

Bash script how to display matched words in custom order

The following is the output of the command ads2 cls create However, I’m trying to extract the value of name and state for each node, save them in a variable and display them in the following order: Till now i, with the help of this so much powerful learning site, could extract the values of name and state by executing

grep -r –include not works but –exclude works

In bash, What’s the problem? Answer You are using curly braces incorrectly. The correct syntax would look like (Notice also the addition of the missing file name argument . at the end.) You can see what’s going wrong by putting an echo in front and examining what the shell expands the braces to.