Grep for Multiple Patterns or Strings

The basic grep syntax when searching multiple patterns in a file includes using the grep command followed by strings and the name of the file or its path. The patterns need to be enclosed using single quotes and separated by the pipe symbol. Use the backslash before pipe | for regular expressions.

1. How do you grep multiple lines after a match?
2. How do I combine two grep commands?
3. How do you grep with and condition?
4. Which of the following symbols are used for matching multiple patterns?
5. Can you grep for multiple patterns in a file?
6. How do you get 10 lines after grep?
7. Does grep support regex?
8. How do you concatenate a command in Linux?
9. How do you use awk?
10. How do you grep special characters?
11. Which command print all lines with exactly two characters?
12. Which option is used with grep command for ignoring the case in pattern searching?

How do you grep multiple lines after a match?

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 combine two grep commands?

Two possibilities:

1. Group them: grep 'substring1' file1.txt grep 'substring2' file2.txt > outfile.txt. ...
2. Use the appending redirection operator >> for the second redirection: grep 'substring1' file1.txt > outfile.txt grep 'substring2' file2.txt >> outfile.txt.

How do you grep with and condition?

Grep OR Operator

1. Grep OR Using \| If you use the grep command without any option, you need to use \| to separate multiple patterns for the or condition. ...
2. Grep OR Using -E. grep -E option is for extended regexp. ...
3. Grep OR Using egrep. egrep is exactly same as 'grep -E'. ...
4. Grep OR Using grep -e.

Which of the following symbols are used for matching multiple patterns?

Explanation: Most of the regular expression character are used for matching patterns, but there are two symbols that are used for matching pattern at beginning or end of a line. These symbols are ^ and $. 7. The following command will match the lines beginning with '2'.

Can you grep for multiple patterns in a file?

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. The tool prints all lines that contain the words you specify as a search pattern.

How do you get 10 lines after grep?

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. And if you need to print 10 lines of leading and trailing output context.

Does grep support regex?

Grep Regular Expression

GNU grep supports three regular expression syntaxes, Basic, Extended, and Perl-compatible. In its simplest form, when no regular expression type is given, grep interpret search patterns as basic regular expressions.

How do you concatenate a command in Linux?

The semicolon (;) operator allows you to execute multiple commands in succession, regardless of whether each previous command succeeds. For example, open a Terminal window (Ctrl+Alt+T in Ubuntu and Linux Mint). Then, type the following three commands on one line, separated by semicolons, and press Enter.

How do you use awk?

awk Scripts

1. Tell the shell which executable to use to run the script.
2. Prepare awk to use the FS field separator variable to read input text with fields separated by colons ( : ).
3. Use the OFS output field separator to tell awk to use colons ( : ) to separate fields in the output.
4. Set a counter to 0 (zero).

How do you grep special characters?

To match a character that is special to grep –E, put a backslash ( \ ) in front of the character. It is usually simpler to use grep –F when you don't need special pattern matching.

Which command print all lines with exactly two characters?

Grep searches the named input FILEs (or standard input if no files are named, or the file name – is given) for lines containing a match to the given PATTERN. By default, grep prints the matching lines. In addition, two variant programs egrep and fgrep are available. Egrep is the same as grep -E.

Which option is used with grep command for ignoring the case in pattern searching?

7. Which option is used with grep command for ignoring the case in pattern searching? Explanation: When we want to search a pattern using grep command and we want to ignore the case or we are not sure of the case, we've to use the -i option. This option ignores the case the pattern matching.