How do you grep a few lines?

How do you grep a few lines?

For BSD or GNU grep you can use -B num to set how many lines before the match and -A num for the number of lines after the match. 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.

How do you grep before and after lines?

To also show you the lines before your matches, you can add -B to your grep. The -B 4 tells grep to also show the 4 lines before the match. Alternatively, to show the log lines that match after the keyword, use the -A parameter. In this example, it will tell grep to also show the 2 lines after the match.

How do I grep and print next line?

You can use grep with -A n option to print N lines after matching lines. Using -B n option you can print N lines before matching lines. Using -C n option you can print N lines before and after matching lines.

How do you concatenate a command in Linux?

4. Concatenate Commands Conditionally

1. 4.1. Concatenate Commands With “&&“ The “&&” or AND operator executes the second command only if the preceding command succeeds.
2. 4.2. Concatenate Commands With “||” The “||” or OR operator executes the second command only if the precedent command returns an error.

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).

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.

Is there a way to add multiple patterns to grep?

This option treats the pattern you used as an extended regular expression. The deprecated version of extended grep is egrep. Another option is to add multiple separate patterns to the grep command. To do so, use the -e flag and keep adding the desired number of search patterns:

When do you use grep instead of egrep?

If you need both words are close each other, for example no more than 3 lines, you can do this: Same example but filtering only *.txt files: And also you can replace grep command with egrep command if you want also find with regular expressions.