You should get a grip on the Linux grep command. In this article let us review 15 practical examples of Linux grep command that will be very useful to both newbies and experts. First create the following demo_file that will be used in the examples below to demonstrate grep command. $ cat demo_file Grep Command In Unix With Example 3. Piping Command In Unix With Example 4. Sort And Uniq Command In Unix With Example 5. Head, Tail And Tr Command In Unix With Example 6. Shell Scripting Introduction And Example 7. Conditional Statements In Bash 8. Loops In Unix With Example The grep UNIX command allows you to find lines in files that contain key words or phrases. With this command, it is possible to perform a quick search of a file or directory without having to look at each file via a text editor or the UNIX more command.. Simply put, grep searches an entire file for the pattern you want and displays its findings. grep is a command-line utility for searching plain-text data sets for lines that match a regular expression.Its name comes from the ed command g/re/p (globally search a regular expression and print), which has the same effect: doing a global search with the regular expression and printing all matching lines. Linux grep command usage with examples. The grep command which stands for "global regular expression print," processes text line by line and prints any lines which match a specified pattern. The grep command is used to search text or searches the given file for lines containing a match to the given strings or words. The grep utilities are a family of Unix tools, including grep, egrep, and fgrep, that perform repetitive searching tasks.The tools in the grep family are very similar, and all are used for searching the contents of files for information that matches particular criteria. For most purposes, you'll want to use fgrep, since it's generally the fastest. UNIX Basic commands: grep The grep command allows you to search one file or multipl