How do I grep a line in Linux?

How do you grep a line?

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 a whole line in Linux?

To Show Lines That Exactly Match a Search String

The grep command prints entire lines when it finds a match in a file. To print only those lines that completely match the search string, add the -x option. The output shows only the lines with the exact match.

Does grep go line by line?

grep searches the named input FILEs (or standard input if no files are named, or if a single hyphen-minus (-) is given as file name) for lines containing a match to the given PATTERN. By default, grep prints the matching lines. … fgrep is the same as grep -F.

How do I grep a string in a file?

Searching for Patterns With grep

  1. To search for a particular character string in a file, use the grep command. …
  2. grep is case sensitive; that is, you must match the pattern with respect to uppercase and lowercase letters:
  3. Note that grep failed in the first try because none of the entries began with a lowercase a.

How do you grep two lines in Unix?

How do I grep for multiple patterns?

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

How do I grep next 10 lines?

4 Answers. 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!

How do I use find in Linux?

The find command is used to search and locate the list of files and directories based on conditions you specify for files that match the arguments. find command can be used in a variety of conditions like you can find files by permissions, users, groups, file types, date, size, and other possible criteria.

What is the use of awk in Linux?

Awk is a utility that enables a programmer to write tiny but effective programs in the form of statements that define text patterns that are to be searched for in each line of a document and the action that is to be taken when a match is found within a line. Awk is mostly used for pattern scanning and processing.

What does grep do in Linux?

What is grep ? You use the grep command within a Linux or Unix-based system to perform text searches for a defined criteria of words or strings. grep stands for Globally search for a Regular Expression and Print it out.

How do you grep a line and 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 display the nth line in Linux?

Below are three great ways to get the nth line of a file in Linux.

  1. head / tail. Simply using the combination of the head and tail commands is probably the easiest approach. …
  2. sed. There are a couple of nice ways to do this with sed . …
  3. awk. awk has a built in variable NR that keeps track of file/stream row numbers.

Which option is used with grep command for deleting lines?

8. Which option is used with grep command for deleting lines? Explanation: grep can play an inverse role; the -v (inverse) option selects all lines except those containing the pattern.

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