Explain the significance of option –I, -v with grep command

 

• grep (General Regular Expression Print) 

$ grep options pattern files

 

grep searches the named files (or standard input if no files are named) for lines that match a given pattern. Thedefault behavior of grep is to print out the matching lines. For example:$ grep hello *.txtsearches all text files in the current directory for lines containing "hello". options that grep provides are: 

-i (Displays list of filenames only) 

-v (print out the lines that don't match the pattern)

          $ grep -vi hello *.txt 

 

searches all text files in the current directory for lines that do not contain any form of the word hello (e.g. Hello,HELLO, or hELlO).