Sed delete lines matching multiple patterns

Posted by

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Ask Ubuntu is a question and answer site for Ubuntu users and developers. It only takes a minute to sign up.

Now, I'm trying to use those numbers to delete all lines that come after the pattern to the file end. Meaning, match every line from the first one to the one with pattern and delete all the non-matched lines. So, replace pattern with your pattern. To actually edit files rather than print the edited stream to stdoutyou can use the -i flag:. You can make a backup of the original file by adding an extension for the old file to -i. Take care here - you must not include a space before the extension.

For example, to act on all the non-hidden files in the current directory you could use:. While the variable stop is 0 which is is, by defaultawk will print the current line.

sed delete lines matching multiple patterns

Try this shell script. It take 2 argument as input. First argument is the input filename. And the second argument is the required pattern to search. It will delete lines after the pattern is matched for first time. Ubuntu Community Ask! Sign up to join this community.

The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Delete lines that come after a line with a specific pattern in Shell Ask Question. Asked 2 years ago. Active 2 years ago. Viewed 17k times. I'm trying to delete all lines comes after a specific pattern in files.

I have many files, which all have the same structure: Example: file1 line Today's Posts. Quick Links. Search Forums. Show Threads. Show Posts. Shell Programming and Scripting. Registered User. Join Date: Oct Hi all, I have the following data in a file x. Last edited by not4google; at AM. Reason: Ammended Title. Join Date: Feb Code :. Join Date: Sep I tried but it doesnt like this: Code :. Thanks for the quick responses, I want to search for a particular string and then append to the first line, is this possible with something like the following: Code :.

The easiest way to find out is to try and to experiment. Test Your Knowledge in Computers Difficulty: Medium. Submit Answer.

Delete lines based on pattern match. Whenever the pattern ORA is encountered, I want to delete the line which has this pattern and 3 lines below it. Sed: how to merge two lines moving matched pattern to end of previous line. Delete lines and the first pattern between 2 matched patterns.

Hi, i need help to delete all the lines between 2 matched patterns and the first pattern must be deleted too. Sed delete blank lines upto first pattern match. Hi Im trying to do the following in sed. I want to delete any blank line at the start of a file until it matches a pattern and then stops. I have this input file that I need to remove lines which represents more than 30 days of processing. First of all, I know this can be more eassily done with perl or other scripting languages but, that's not the issue.

I need this in sed.

Unix Sed Command to Delete Lines in File - 15 Examples

Sed to delete exactly match pattern and print them in other file. Hi there, I need help about using sed. Iam using sed to delete and print lines that match the port number as listed in sedfile.

I am using -d and -p command for delete match port and print them respectively. However, the output is not synchonize where the total deleted lines is not similar withFor example, one might want to change. I initially thought it might be more efficient not to keep the complete input in the hold buffer, so I modified the algorithm to print out the string whenever a match is found:.

In the last example, sed concatenates lines only until it finds a match, and then it prints the line after substituting the text.

sed delete lines matching multiple patterns

Then, it starts again to concatenate the following lines. However, that approach is usually massively inefficient, as the regex work increases logarithmically. H if the last line then When trying to replicate this example by running the command suggested: sed -n '1h;1!

Never mind. I figured it out. Basically, you have to escape the backslash on the closing h2 tag. Your email is never shared.

I try to make this working to my needs but with no success […]. Austin Matzko's Blog A blog about philosophy, Christianity, web development and whatever else I feel like writing about. Skip to content. This entry was written by filosofoposted on April 26, at pmfiled under Computers and tagged bashgrepLinuxregexsedshell.

Shell Programming and Scripting

Bookmark the permalink. Follow any comments here with the RSS feed for this post. Post a comment or leave a trackback: Trackback URL. Thank you for this. You are a philosopher and a poet. Hi, filosofo Maybe I misunderstood something, nut I created the following bash script:! Hi, filosofo Maybe I misunderstood something, but I created the following bash script:!

Frank wrote on February 22, at pm. Post a Comment Your email is never shared.Welcome to the most active Linux Forum on the web. Welcome to LinuxQuestions. You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features.

Registration is quick, simple and absolutely free. Join our community today! Note that registered members see fewer ads, and ContentLink is completely disabled once you log in. Are you new to LinuxQuestions. If you need to reset your password, click here.

Subscribe to RSS

Having a problem logging in? Please visit this page to clear all LQ-related cookies. Introduction to Linux - A Hands on Guide This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter. For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration.

This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. They hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.

Click Here to receive this Complete Guide absolutely free. I have to construct a maintenance program, part of this program is the interrogation of log files. Ordinarily a grep or sed would sort me right out however this problem has a few other restrictions.

I have to initially get the current date from the system and then match this to entries in a log file. Not a problem, already done. However once I have located a matching line I then have to step over the next lines looking for another pattern and, if found, write these entries to a file. I can ONLY use either grep, sed or awk to do this.The grepegrepsed and awk are the most common Linux command line tools for parsing files. Cool Tip: Find and validate email addresses with grep command!

The best regular expression for email addresses! It is also often required to grep a file for multiple patterns — when it is needed to find all the lines in a file, that contain not one, but several patterns.

sed delete lines matching multiple patterns

Note, that you can both find the lines in a file that match multiple patterns in the exact order or in the any order. Use one of the following commands to find and print all the lines of a file, that match multiple patterns. Cool Tip: The server is out of memory? Bash one liner for the true Linux admins!

Cool Tip: Find and validate IP addresses with grep command! The best regular expression for IP addresses! You can certainly pipe grep into another grep in bash. In your case, you need to escape the octothorp or surround it with quotes. All of the following will work in bash:.

This site uses Akismet to reduce spam. Learn how your comment data is processed. Comments 5 text-processing. Leave a Reply Cancel reply. We use cookies to ensure that we give you the best experience on our website.

If you continue to use this site we will assume that you are happy with it.Thank you for this great article. I will use as a reference!

I have a question about number How to delete line before Linux only if it is empty or has only white spaces? Thank you again! Thank you Guru! You are very good! I am new to Shell scripting, only been at it for a few months.

I bookmarked this article for future reference. Excellent article! How can I do to delete all lines between 2 parameters? Thank you in advance. Nice article Good examples. Those should be removed from the file. I am using awk command but how will be the performance if millions of records are there in a file. Whenever a file is big, just make sure every command you use for per record processing should be justified to be there.

For any technical questions, please post the question in our forum: forum. Hi, Very nice read Thanks Dhruuv. The command you used is correct one. However, only if your file content is beginning with ',Pub, Hi, very good example and easy to understand. But i have a question. How to delete lines and matched patterns between 2 patterns without deleting the second pattern?By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

It only takes a minute to sign up. I am trying to remove all instances of a pattern match from a file if it matches a pattern. If there is a match, the complete line with the matching pattern and the next line get removed.

The next line always appears after the line with the pattern match, but in addition it appears in other areas of the file. Is there a way I can remove that next line if and only if it is after the line with the pattern match? N takes the next line into the pattern space as well, and then d deletes the whole thing before moving on to the next line.

But GNU sed will. So if the pattern you want deleted is on the last line and you N it will print. It is sometimes better to keep the buffer full - as in, always holding 2 lines except on the lines you do not want to print.

You might do so like:. That's an example with seq as input.

SED Remove or Replace the Last Word of Each Line Linux Shell tutorial BASH

On every line it swaps hold space and pattern space. If the last held line does not match a 7 in this case it will overwrite the hold space with the current line. It then checks again that the line it just pulled in - the current line - also does not match the 7otherwise it will not print it. So on every line it checks the previous and the current line.

Line 1 looks for lines matching the pattern, sets a flag, and skips the line. Line 2 skips a line when the flag is set, but resets the flag. Line 3 prints lines that weren't skipped by one of the other two lines.

Set skip to the number of lines that should be skipped in addition to the matched line.


Leave a Reply

Your email address will not be published. Required fields are marked *