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Grep commands how to#

If this option is used multiple times or is combined with the Patterns separate each pattern from the next. Use patterns as one or more patterns newlines within I hope you have now enough knowledge of grep command and how it is used in various conditions.Next: General Output Control, Previous: Generic Program Information, Up: Command-line Options 2.1.2 Matching Control ¶ -e patterns -regexp= patterns

Grep commands how to#

In the above tutorial, you learned how to use the grep command to search for a specific string in files. You can print only matching patterns using the -o option.įor example, search for file1.txt that matches the string/pattern linux with the following command: grep -o linux file1.txt You can also display one line before and after the matching string using the option c and n with grep command.įor example, display one line before and after the matching string linux in file4.txt, run the following command: grep -n -C 1 linux file4.txtīy default, grep command prints the entire line which matches a pattern. You can use grep with -n option to print line numbers with matching patterns.įor example, to display line number that matches the pattern linux in the current directory, run the following command: grep -n linux *įile1.txt:1:tecadmin is a popular linux blogįile2.txt:2:linux is made by linus torvalds.įile2.txt:3:linux is most popular operating system.įile3.txt:2:Ubuntu is a linux operating system You can use grep with -c option to display all files with the number of lines that matches the given string.įor example, to display all files with the number of lines that matches a string linux in the current directory, run the following command: grep -c linux *ĭisplay Line Number with Matching Pattern You can display only filenames that contain a specific string using -l option.įor example, list all filenames in the current directory that matches the string tecadmin, run the following command: grep -l tecadmin * To List Filenames That Matches Specific Pattern This command will exclude all the lines that contain the string linux: You can use grep command with -v option to print all lines that do not match a specific pattern of characters.įor example, print all lines that don’t contain the string linux in file1.txt and file2.txt, run the following command: grep -v linux file1.txt file2.txt This command will print all lines that contain a word linux in all files in the current directory and sub-directories:įile3.txt:Ubuntu is a linux operating system To search for a string linux in all files in the current directory and sub-directories, run the following command: grep -r linux *.This command will print all lines that contain a word linux in file1.txt and file2.txt:įile1.txt:tecadmin is a popular linux blogįile2.txt:Linux is an open-source operating system.įile2.txt:linux is made by linus torvalds.įile2.txt:linux is most popular operating system. To search for a string linux in file file1.txt and file2.txt, run the following command: grep -i linux file1.txt file2.txt.To Search a Specific String in Multiple File This command will print all lines that contain a word tecadmin case insensitively:

To search for a string tecadmin case insensitively in the file file1.txt, run the following command: grep -i tecadmin file1.txt.

This command will print all lines that contain a whole word tecadmin:

To search for an exact string tecadmin in the file file1.txt, run the following command: grep -w tecadmin file1.txt.

This command will print all lines that contain a word tecadmin:

To search for a string tecadmin in the file file1.txt, run the following command: grep tecadmin file1.txt.

A system running the Linux operating system.

In this tutorial, we will show you how to use the Grep command with some practical examples.

Suggested Read: 12 Awesome Linux Find Command Examples.

So Grep command can be used to search some kind of text, word, pattern or sentence in a text file or a number of text files. Basically, Grep searches a text file for the specified regular expression and outputs any line containing a match to standard output. Grep is a powerful tool for searching a text, Grep means “Global regular expression print”.