#Centos grep usage how to#

We can use the below options in Linux Grep command to extract the N number of lines matching the containing pattern before/After from the given file.

#Centos grep usage how to#

How to Grep for the lines before and After the pattern occurrence in a file Lets search for the Work Upper from the file with -i option grep]$ grep Upper -i intro-demo.txt Linux Grep Command offers the -i to skip the case and perform the grep]$ grep -i Cent intro.txt The -exclude-dir='Some Directory name' options skips the contents of the mention directory Lets see the Demonstration: $ grep -w -E 'data' * -R -exclude-dir='backup' -exclude-dir='adb-fastboot' -exclude-dir='IntelliJ-IDEA' How to use Linux Grep commmand to ignore the case OR perform Case Insensitive search ? Lets see the Demonstration below grep]$ grep -c 'Linux' intro.txtĤ How to Exclude specific Directories while searching with grep command ? In Linux Grep command we can use the Option -c to get the total occurance Count of the matching pattern/string Intro.txt How to get the number of Count Matches using Grep command ? Using the -l Option of grep command will print all the file names containing the matching string pattern/string literal grep]$ grep -l Linux * How to print the names of all the files matching the string pattern using Linux Grep command. The -v option prints all the lines not matching the given string pattern. How to use the Invert Option in Linux grep command This can be used in conjunction with -o prints only completely matched word string pattern.

Lets us see the Demonstration below: grep]$ grep -w 'Cent' intro.txtĪnd As expected here we have not seen any occurrence of the word Cent from the file although the word Centos was present, But it didnt match because we used -w option to match the word Cent.īut when we grep for the Word Linux then we can see the exact occurrence of the word and the matching lines are printed. So far we have seen only the matching string pattern, but if you want to find the occurance of particular word then use grep -w Option grep]$ grep -b 'Linux' intro.txtĦ6:There following are Most popular Linux server Distributions:Ģ17:This is a Demonstration of Linux grep command The -b Option prints the subsequent starting offset index of the matching word from the lines within the given filename. Print the sequence number of lines that contain the matched string pattern can be achieved using -n Option: grep]$ grep -n 'Linux' intro.txtĤ:There following are Most popular Linux server Distributions:ġ1:This is a Demonstration of Linux grep command How to print the sequence number of matched pattern in file using Grep command in Linux? Intro-demo.txt:This is a Demonstration of Linux grep command Intro-demo.txt:5) SUSE Linux Enterprise Server Intro-demo.txt:1) Redhat Enterprise Linux Intro-demo.txt:There following are Most popular Linux server Distributions: Intro.txt:This is a Demonstration of Linux grep command Intro.txt:5) SUSE Linux Enterprise Server Intro.txt:There following are Most popular Linux server Distributions: Lets see the Demonstration grep]$ grep 'Linux' intro.txt intro-demo.txt Searching for a pattern on multiple files using grep command Lets see the Demonstration grep]$ grep 'Linux' intro.txt The grep command sample search syntax is $ grep “string pattern” $ cat | grep 'string pattern' Let’s start with search of a string pattern in the given file This is a Demonstration of Linux grep command There following are Most popular Linux server Distributions: We now have a text file with Following content.īelow is the content of the file called intro.txt. In this section we will focus on the important scenarios and provide the realtime explanation about the Various Grep command options offered in linux command line. The grep command is one of the most essential commands in Unix/Linux ecosystem, It is used to extract match and find the occurrence of string literals and patterns among the text files.