Regex: Remove lines containing "help", etc
I have a long document of commands. Using Notepad++ or regex, I want to delete all lines containing "help" including keyboard_help, etc.
How can this be done?
This is also possible with Notepad++:
- Go to the search menu, Ctrl + F, and open the Mark tab.
Check Bookmark line (if there is no Mark tab update to the current version).
Enter your search term and click Mark All
- All lines containing the search term are bookmarked.
Now go to the menu Search → Bookmark → Remove Bookmarked lines
Another way to do this in Notepad++ is all in the Find/Replace dialog and with regex:
Ctrl + h to bring up the find replace dialog.
Find what:text box include your regex:
\ris optional in case the file doesn't have Windows line endings).
Replace with:text box empty.
Make sure the Regular expression radio button in the Search Mode area is selected. Then click
Replace Alland voila! All lines containing your search term
helphave been removed.
Read more... Read less...
Easy task with
grep -v help filename
> newFileName to redirect output to a new file.
To clarify it, the normal behavior will be printing the lines on screen. To pipe it to a file, the
> can be used. Thus, in this command:
grep -v help filename > newFileName
-vis a flag to inverse the output. By defaulf,
grepprints the lines that match the given pattern. With this flag, it will print the lines that don't match the pattern.
helpis the pattern to match
filenameis the name of the input file
>redirects the output to the following item
newFileNamethe new file where output will be saved.
As you may noticed, you will not be deleting things in your file.
grep will read it and another file will be saved, modified accordingly.
You can do this using sed:
sed '/help/ d' < inputFile > outputFile
Search with a regular expression:
If you're on Windows, try
findstr. Third-party tools are not needed:
findstr /V /L "searchstring" inputfile.txt > outputfile.txt
It supports regex's too! Just read the tool's help
P.S. If you want to work with big, huge files (like 400 MB log files) a text editor is not very memory-efficient, so, as someone already pointed out, command-line tools are the way to go. But there's no grep on Windows, so...
I just ran this on a 1 GB log file, and it literally took 3 seconds.