linux grep search all files in directory

Linux grep search all files in directory how to#

Regular expressions consist of letters and numbers, in addition to characters with special meaning to grep. You can also use the grep command to search for targets that are defined as patterns by using regular expressions.

Linux grep search all files in directory how to#

The following example shows how to search through all the files in the current directory for lines that do not contain the letter e. To search for all the lines of a file that do not contain a certain string, use the -v option to grep. Searching for Lines Without a Certain String When it finds a pattern that matches in more than one file, it prints the name of the file, followed by a colon, then the line matching the pattern.Īlaska:Alaska is the largest state in the United States. The grep command can search for a string in groups of files. To find a pattern that is more than one word long, enclose the string with single or double quotation marks. The search provides the following results. The second part of the command line pipes that list through grep, looking for the pattern Sep. The first part of this command line produces a list of files ending in. ps” and were created in the month of September. The following example displays files that end in “. To use grep as a filter, you must pipe the output of the command through grep. You can use the grep command as a filter with other commands, enabling you to filter out unnecessary information from the command output. Note that grep failed in the first try because none of the entries began with a lowercase a. Grep is case sensitive that is, you must match the pattern with respect to uppercase and lowercase letters: Note that more than one line might match the pattern you give.

$ grep Poe extensions Edgar Allan Poe x72836 Strings can include blank spaces, punctuation, and invisible (control) characters.įor example, to find Edgar Allan Poe's telephone extension, type grep, all or part of his name, and the file containing the information: A single letter is a string, as is a word or a sentence.

In this example, string is the word or phrase you want to find, and file is the file to be searched.Ī string is one or more characters. To search for a particular character string in a file, use the grep command.