How do you grep either A or B in Linux?

How do you grep two conditions?

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 you grep between two patterns in Linux?

You can achieve multiline match in grep , but you need to use perl-regexp for grep ( -P – which is not supported on every platform, like OS X), so as workaround we’re replacing new lines with _ character and after grep , we’re changing them back.

How do you grep for or?

Grep OR Using -E

grep -E option is for extended regexp. If you use the grep command with -E option, you just need to use | to separate multiple patterns for the or condition. For example, grep either Tech or Sales from the employee. txt file.

Can we grep multiple strings?

Grep is a powerful utility available by default on UNIX-based systems. The name stands for Global Regular Expression Print. … 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.

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Why is grep not working?

The grep * is going to do “globbing” expansion against the files in the current directory. … If the current directory was empty, you would end up searching for * . But that won’t work either because the first command line argument is a regex, and “*” is not a valid regex.

What options can be used with grep command?

The grep command supports a number of options for additional controls on the matching:

  • -i: performs a case-insensitive search.
  • -n: displays the lines containing the pattern along with the line numbers.
  • -v: displays the lines not containing the specified pattern.
  • -c: displays the count of the matching patterns.

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.

How does grep work in Linux?

Grep is a Linux / Unix command-line tool used to search for a string of characters in a specified file. The text search pattern is called a regular expression. When it finds a match, it prints the line with the result. The grep command is handy when searching through large log files.

What is grep command with example?

grep command in Unix/Linux. The grep filter searches a file for a particular pattern of characters, and displays all lines that contain that pattern. The pattern that is searched in the file is referred to as the regular expression (grep stands for globally search for regular expression and print out).

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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.

How do I use find in Linux?

Basic Examples

  1. find . – name thisfile.txt. If you need to know how to find a file in Linux called thisfile. …
  2. find /home -name *.jpg. Look for all . jpg files in the /home and directories below it.
  3. find . – type f -empty. Look for an empty file inside the current directory.
  4. find /home -user randomperson-mtime 6 -iname “.db”

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