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How to grep multiple strings from text file?
However, there a number of ways to achieve what you’re trying to accomplish. Here’s one approach: Use a single regular expression with an “or” operator. Using Perl regular expressions, it will look like the following: EDIT: As you mentioned in your comment, you want to use a list of words to find from a file and search in a full directory.
Is there a way to include all files in grep?
To include all files, use sudo with the grep command. Enter the sudo password, and grep will search through all files. The grep command searches only in the current directory when you use the asterisk wildcard. To include all subdirectories when searching for multiple patterns, add the -R operator to grep:
Where can I find the output of grep?
The output will return results from all files the grep command found in the /var/log/ directory and its subdirectories. In this tutorial, you learned how to use grep to search multiple words or string patterns in a file.
What’s the difference between extended Grep and egrep?
The egrep command is an outdated version of extended grep. It does the same function as grep -E. The difference between grep and extended grep is that extended grep includes meta characters that were added later. These characters are the parenthesis (), curly brackets {}, and question mark.
Is there a way to add multiple patterns to grep?
This option treats the pattern you used as an extended regular expression. The deprecated version of extended grep is egrep. Another option is to add multiple separate patterns to the grep command. To do so, use the -e flag and keep adding the desired number of search patterns:
How does grep search for lines of text?
By default, grep displays the matched lines, and it can be used to search for lines of text that match a regular expression (s), and it outputs only the matched lines. The basic grep command syntax is as follows:
How to grep for more than two words?
To search for more than two words, keep adding them in the same manner. For example, to search for three words, add the desired string of characters followed by a backslash and pipe: Let’s see how the above grep command looks when using grep -E, egrep, and grep -e: