Here’s an example where we search a text document for a string. While you can use grep to search the output piped from other command-line tools, you can also use it to search documents directly. Grep will accept both single quotes and double quotes, so wrap your string of text with either. For example, what if we needed to search for the “My Documents” directory instead of the single-worded “Documents” directory? $ ls | grep 'My Documents' If you need to search for a string of text, rather than just a single word, you will need to wrap the string in quotes. So if grep returns nothing, that means that it couldn’t find the word you are searching for. If the Documents folder didn’t exist, grep wouldn’t return any output. $ ls | grep DocumentsĪs you can see in the screenshot above, using the grep command saved us time by quickly isolating the word we searched for from the rest of the unnecessary output that the ls command produced. Let’s look in our home directory for a folder called Documents.Īnd now, let’s try checking the directory again, but this time using grep to check specifically for the Documents folder. That’s something you would use the “ls” command for.īut, to make this whole process of checking the directory’s contents even faster, you can pipe the output of the ls command to the grep command.

Say that you need to check the contents of a directory to see if a certain file exists there. Let’s look at some really common examples. You can use it to search a file for a certain word or combination of words, or you can pipe the output of other Linux commands to grep, so grep can show you only the output that you need to see. Grep is a command-line tool that Linux users use to search for strings of text. Difference between grep, egrep fgrep, pgrep, zgrep.

Linux grep command