![]() $ grep -E "ismail|ali" *.txt Match In Multiple FilesĪs we can see matched files also printed with the matched text. We have also the ability to search and match in multiple files. We will use \. )" data.txt Match IP Address or Domain Name Match In Multiple Files This may be a regular operation while searching in log files. Now we will look useful example which provides IP address or domain names. $ grep -E "is.ail|al." data.txt Match Multiple Pattern or Regex Match IP Address or Domain Name We can specify standard regular expression with the same way. Now we want to use multiple regular expression or pattern in our match term. $ grep -E "ismail|ali" data.txt Match Multiple Strings Match Multiple Pattern or Regex ![]() The matching strings will be ismail and ali . In this example we will use a file named data.txt as a text. We will match given multiple strings inside a given text. E means extended grep which will enable extended regular expression features to use. We can use grep command with -E option or egrep command which is the alias of the grep -E . Which application will be most suitable for you depends on your needs and preferences. There are many different applications that can do a good job for you. How To Use Regular Expression – Regex In Bash Linux? Grep -E or Egrepīefore starting examples we look different commands which provides same functionality. For Linux users, the need to search for words in one or multiple files arises quite often. If you need more general tutorial about regex please look following article. In this tutorial we will look different examples about these features. One of the most used feature is to match two or more, multiple string, patterns or regex. The output highlights the string you wanted to grep.Grep provides a lot of features to match strings, patterns or regex in a given text. Since grep does not support the pipe symbol as the alternation operator, you need to use the escape character (backslash \) to tell the grep command to treat the pipe differently.įor example, to search for the words extraand valuein the sample.txt file use this command: grep 'extra\|value' sample.txt Do not forget to use the backslash before the pipe character. In the examples below, we will use grep instead of extended grep. We stored the file in the directory of the test user, that is, in /home/test/sample.txt How to Grep Multiple Patterns in a File In our case, we named the file sample.txt and added a few paragraphs of text. To make sure you understand how to use grep to search multiple strings, we suggest creating a file with some text on which we are going to try out a couple of different use cases. Examples of Using Grep for Multiple Strings, Patterns and Words The pipe character | is also treated as a meta character in extended grep. These characters are the parenthesis (), curly brackets, and question mark. The difference between grep and extended grep is that extended grep includes meta characters that were added later. The egrep command is an outdated version of extended grep. To do so, use the -e flag and keep adding the desired number of search patterns: grep -e pattern1 -e pattern2 fileName_or_filePath What is the Difference Between grep, grep -E, and egrep? egrep 'pattern1|pattern2' fileName_or_filePathĪnother option is to add multiple separate patterns to the grep command. The deprecated version of extended grep is egrep. grep -E 'pattern1|pattern2' fileName_or_filePath This option treats the pattern you used as an extended regular expression. The latest way to use grep is with the -Eoption. grep 'pattern1\|pattern2' fileName_or_filePath Use the backslash before pipe | for regular expressions. The patterns need to be enclosed using single quotes and separated by the pipe symbol. 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. ![]() A user with permissions to access the necessary files and directories The grep method of multiple strings or patterns can be used if the operating system contains files with multiple strings and the user wants to target or reach. ![]()
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