How to show same number of lines before and after in grep?

How to show same number of lines before and after in grep?

If you want the same number of lines before and after you can use -C num. This will show 3 lines before and 3 lines after. -A and -B will work, as will -C n (for n lines of context), or just -n (for n lines of context… as long as n is 1 to 9).

How to get rid of duplicates in grep output?

Problem is sometimes i have multiple cases in the same file so i would like to remove the duplicates files (the cases would be different so it’s not possible). into just the first results found without losing all the rest of the data in the file. i’m looking to get rid of the multiple occurrences in the same file so it should look like this:

How can I grep all files in that folder without listing duplicates?

How can I grep all files in that folder without listing any duplicate of lines with identical text? It is similar to sort -u but it does not sort the input and it gives output while running. If you want the file name and do not want duplicate lines from any of the files (File names must not contain TAB ( )):

Why does grep not print the file name?

The -t: and -k2 options of sort will cause it to ignore the file name when doing the sorting and merging. which will not print the name of the files matching, but will be fast. If you need the filename also (separated with : ).

Can you use grep to search multiple strings?

You can grep multiple strings in different files and directories. The tool prints all lines that contain the words you specify as a search pattern. In this guide, we will show you how to use grep to search multiple words or string patterns.

What’s the best way to match a digit in grep?

to match a digit in grep you can use [0-9]. To match anything but a digit, you can use [^0-9]. Since that can be any number of , or no chars, you add a “*” (any number of the preceding). So what you’ll want is logically (anything not a digit or nothing)* (any single digit) (anything not a digit or nothing)* .

Is there a way to filter out duplicate lines in grep?

Closed 2 years ago. Your question is not quite clear, but you can filter out duplicate lines with uniq: Not the answer you’re looking for? Browse other questions tagged linux grep or ask your own question.

Can you use grep to match lines that do not contain Foo or bar?

Lines containing neither foo nor bar which contain either foo2 or bar2: And so on. In your case, you presumably don’t want to use grep, but add instead a negative clause to the find command, e.g. If you want to include wildcards in the name, you’ll have to escape them, e.g. to exclude files with suffix .log: Highly active question.

How to grep for groups of n digits, but no more than n?

Here it is: grep a line from a file which contains 4 numbers in a row but not more than 4. I’m not sure how to approach this. I can search for specific numbers but not their amount in a string.

Why do I use the-X flag in grep?

The -x flag makes grep display only lines where the entire line matches (rather than any line containing a match). I’ve used a Perl regular expression because I think the brevity of \\d and \\D substantially increase clarity in this case.

How can I use grep for multiple strings?

For example, to show the count of multiple matches in the bootstrap.log file, enter: The output prints the number of matches. This way, you can quickly determine if the number of warnings and errors increased. You can use grep to search multiple strings in a certain type of file only.

Is there a way to include all files in grep?

To include all files, use sudo with the grep command. Enter the sudo password, and grep will search through all files. The grep command searches only in the current directory when you use the asterisk wildcard. To include all subdirectories when searching for multiple patterns, add the -R operator to grep:

Where can I find the output of grep?

The output will return results from all files the grep command found in the /var/log/ directory and its subdirectories. In this tutorial, you learned how to use grep to search multiple words or string patterns in a file.

How to grep for contents after pattern in Linux?

The file is sent via stdin ( < file.txt sends the contents of the file via stdin to the command on the left) to an awk script that, for each line that contains potato: ( if (/potato:/) returns true if the regular expression /potato:/ matches the current line), prints the second field, as described above.

What’s the difference between a 5 and a 5 in grep?

-5 gets you 5 lines above and below the match ‘thestring’ is equivalent to -C 5 or -A 5 -B 5. Grep has an option called Context Line Control, you can use the –context in that, simply, If you search code often, AG the silver searcher is much more efficient (ie faster) than grep.

How to return only the portion of a line after a matching pattern?

So pulling open a file with cat and then using grep to get matching lines only gets me so far when I am working with the particular log set that I am dealing with. It need a way to match lines to a pattern, but only to return the portion of the line after the match. The portion before and after the match will consistently vary.

What does context mean in grep 2.1.5?

2.1.5 Context Line Control. Context lines are non-matching lines that are near a matching line. They are output only if one of the following options are used. Regardless of how these options are set, grep never outputs any given line more than once.

How to limit the number of characters in a grepl file?

Assuming the script is saved as grepl, then grepl pattern file_with_long_lines should display the matching lines but with only 10 characters around the matching string. Thanks for contributing an answer to Unix & Linux Stack Exchange!

What does the pattern { 2 } mean in grep?

PATTERN) {2}) – a negative lookahead that fails the match that is immediately to the right of the current location, i.e. the start of string, if there are two ( {2}) consecutive occurrences of: That leaves us with lines either with exactly one # or none.

Which is faster to search code AG or grep?

If you search code often, AG the silver searcher is much more efficient (ie faster) than grep. You show context lines by using -C option. You can use option -A (after) and -B (before) in your grep command. Try grep -nri -A 5 -B 5 .

What’s the best way to limit the output of grep?

Limit grep Output to a Fixed Number of Lines. Individual files, such as log files, can contain many matches for grep search patterns. Limit the number of lines in the grep output by adding the -m option and a number to the command.

How to show before and after matches in grep?

Use –C and a number of lines to display before and after the match: grep –C 2 phoenix sample – this command prints two lines before and after the match. When grep prints results with many matches, it comes handy to see the line numbers. Append the -n operator to any grep command to show the line numbers.

What does grep stand for in Linux command line?

Grep is an acronym that stands for Global Regular Expression Print. Grep is a Linux / Unix command line tool used to search for a string of characters in a specified file.