How do you grep multiple lines?

How do I grep for multiple patterns?

Use single quotes in the pattern: grep ‘pattern*’ file1 file2.
Next use extended regular expressions: egrep ‘pattern1|pattern2’ *. py.
Finally, try on older Unix shells/oses: grep -e pattern1 -e pattern2 *. pl.
Another option to grep two strings: grep ‘word1\|word2’ input.

How do you grep multiple lines after a match?

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 I grep next 10 lines?

You can use the -B and -A to print lines before and after the match. Will print the 10 lines before the match, including the matching line itself. -C 10 will print out 10 lines before AND after in one fell swoop!

Can you grep multiple files?

Grep is a powerful utility available by default on UNIX-based systems. The name stands for Global Regular Expression Print. By using the grep command, you can customize how the tool searches for a pattern or multiple patterns in this case. You can grep multiple strings in different files and directories.

How do I display the 10th line of a file?

Type the following head command to display first 10 lines of a file named “bar.txt”:

head -10 bar.txt.
head -20 bar.txt.
sed -n 1,10p /etc/group.
sed -n 1,20p /etc/group.
awk ‘FNR <= 10’ /etc/passwd.
awk ‘FNR <= 20’ /etc/passwd.
perl -ne’1..10 and print’ /etc/passwd.
perl -ne’1..20 and print’ /etc/passwd.

How do I print 5 lines after grep?

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 grep a line after?

Show lines before and after with grep

-A num. Print num lines of trailing context after each match. See also the -B and -C options.
-B num. Print num lines of leading context before each match. See also the -A and -C options.
-C [num] Print num lines of leading and trailing context surrounding each match.

How do I limit grep results?

5 Answers. From man grep : -m NUM, –max-count=NUM Stop reading a file after NUM matching lines.

How do I print the 25th line in a file?

bhanu_tadiboina

bhanu_tadiboina. Answered On : May 17th, 2007.
head -25 file| tail -1 goes wrong because if some one deletes some lines even then it gives last line as 25th line.so the right option is tail +25 file| head -1.

How do I extract the second row of a text file?

Ataul

Ataul. Answered On : May 20th, 2015.
Code. head -2 filename | tail -1. Similarly to get the 2nd last line, the order will be reversed that is. tail -2 filename | head -1.

What’s difference between grep, egrep and fgrep in Linux?

egrep and fgrep are deprecated commands and should be avoided.

egrep is equivalent to grep -E command and it allows the use of extended regex.

fgrep is equivalent to grep -F command and it uses a fixed string for search and hence it performs a faster search.

What does this grep expression mean?

Grep Regular Expression A regular expression or regex is a pattern that matches a set of strings . A pattern consists of operators, constructs literal characters, and meta-characters, which have special meaning. GNU grep supports three regular expression syntaxes, Basic, Extended, and Perl-compatible.

What does grep -V grep do?

The Story Behind grep. The grep command is famous in Linux and Unix circles for three reasons.

Simple Searches With grep. Matching lines are displayed.

Recursive Searches With grep.

Searching for Whole Words.

Using Multiple Search Terms.

Matching Lines Exactly.

Only Displaying Matching Text.

Counting With grep.

Adding Context.

Showing Matching Files.

What does grep line buffering do?

Beginning at the first line in the file, grep copies a line into a buffer, compares it against the search string, and if the comparison passes, prints the line to the screen. Grep will repeat this process until the file runs out of lines. Notice that nowhere in this process does grep store lines, change lines, or search only a part of a line.