How to Grep for Multiple Strings and Patterns – Guide
Grep is a powerful utility that is available by default on UNIX-based systems. This name stands for Global Regular Expression Printing. Using the grep command, you can customize how the tool looks for patterns or multiple patterns in this case. You can grep multiple strings in different files and directories. This tool prints all lines that contain the words that you specify as the search pattern. In that guide, let’s show you how to use grep to find several words or string patterns. Learn how to use grep more effectively by following the examples in this tutorial. ..
Multiple Grep Patterns
GNU grep supports three regular expression syntaxes: Basic, Extended and Perl compatible. When no regular expression type is specified, grep interprets search patterns as basic regular expressions. To search for multiple patterns, use the OR (toggle) operator.
| grep -i “^([a-zA-Z])$” “.txt” This will search for all text files that contain the string “^([a-zA-Z]*)$”.
“Always enclose the regular expression in single quotes to avoid the shell’s interpretation and expansion of metacharacters.”
To interpret the pattern as an extended regular expression, invoke grep the -E option (or –extended-regexp). When using the extended regular expression, do not escape the | operator:
For more information about how to use regular expressions in your code, check out our Grep article.
Grep Multiple Strings
Fatal, error, and critical strings are the most basic patterns in Nginx log error files.
grep -i “foo” bar This will search for “foo” in the file “bar” and ignore the case of the letters. ..
Grep will output all lines where the string is found, even if it’s embedded in other strings. ..
sed -w ’s/^(.*)$/\1/’ myfile ..
Final note
This guide will teach you how to search for multiple strings and patterns in a text. If you have any questions about the guide, feel free to ask us. Additionally, please share this guide with your friends so they can learn too! ..
