9/1/2023 0 Comments Grep wildcard operatorThe following example will grep all the lines that contain both “Dev” and “Tech” in it (in the same order). Grep -E 'pattern1.*pattern2|pattern2.*pattern1' filename But, you can simulate AND using grep -E option. $ grep -e Tech -e Sales employee.txtĥ00 Randy Manager Sales $6,000 Grep AND 5. Use multiple -e option with grep for the multiple OR patterns. grep -e pattern1 -e pattern2 filenameįor example, grep either Tech or Sales from the employee.txt file. Use multiple -e option in a single command to use multiple patterns for the or condition. Using grep -e option you can pass only one parameter. $ egrep 'Tech|Sales' employee.txtĥ00 Randy Manager Sales $6,000 4. Just use the | to separate multiple OR patterns. egrep 'pattern1|pattern2' filenameįor example, grep either Tech or Sales from the employee.txt file. So, use egrep (without any option) and separate multiple patterns for the or condition. Grep OR Using egrepĮgrep is exactly same as ‘grep -E’. $ grep -E 'Tech|Sales' employee.txtĥ00 Randy Manager Sales $6,000 3. If you use the grep command with -E option, you just need to use | to separate multiple patterns for the or condition.įor example, grep either Tech or Sales from the employee.txt file. $ grep 'Tech\|Sales' employee.txtĥ00 Randy Manager Sales $6,000 2. Without the back slash in front of the pipe, the following will not work. grep 'pattern1\|pattern2' filenameįor example, grep either Tech or Sales from the employee.txt file. If you use the grep command without any option, you need to use \| to separate multiple patterns for the or condition. I prefer method number 3 mentioned below for grep OR operator. Use any one of the following 4 methods for grep OR. You already knew that grep is extremely powerful based on these grep command examples. The following employee.txt file is used in the following examples. The examples mentioned below will help you to understand how to use OR, AND and NOT in Linux grep command. But, you can simulate AND using patterns. Wildcards work just the same if the path is absolute or relative.Question: Can you explain how to use OR, AND and NOT operators in Unix grep command with some examples?Īnswer: In grep, we have options equivalent to OR and NOT operators. In this example we have used an absolute path. Wildcards may be used with any command.Įvery file with an extension of txt at the end. Also note that I'm using ls in these examples simply because it is a convenient way to illustrate their usage. For all the examples below, assume we are in the directory linuxtutorialwork and that it contains the files as listed above. Some more examples to illustrate their behaviour. We are not limited to only certain programs or situations. This is funky as it means we can use them on the command line whenever we want. The program never sees the wildcards and has no idea that we used them. We issue the command:Īnd then executes the program. When we offer it this command it sees that we have used wildcards and so, before running the command ( in this case ls ) it replaces the pattern with every file or directory (ie path) that matches that pattern. It is actually bash (The program that provides the command line interface) that does the translation for us. On first glance you may assume that the command above ( ls ) receives the argument b* then proceeds to translate that into the required matches. The mechanism here is actually kinda interesting. foo3 frog.png secondfile thirdfile video.mpeg.barry.txt blah.txt bob example.png firstfile foo1 foo2.
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