grep - print lines that match patterns
$ cat grep_example.txt
This is line number one
this is line number two
THIS is line number three
this is line 4
This is line 5
To search for the given string in a single file
$ grep "this" grep_example.txt
this is line number two
this is line 4
To check for the given string in multiple files
$ grep "this" grep_example.txt file2.txt
To search case insensitive using grep -i
$ grep -i "4" grep_example.txt
this is line 4
To check for full words using grep -w
$ grep -iw "is" grep_example.txt
This is line number one
this is line number two
THIS is line number three
this is line 4
This is line 5
To search in all files recursively using grep -r
$ grep -r "key_word" *
To count the number of matches using grep -c
$ grep -c this grep_example.txt
2
To find out how many lines that does not match the pattern
$ grep -v -c this grep_example.txt
3
To show line number while displaying the output using grep -n
$ grep -n "this" grep_example.txt
2:this is line number two
4:this is line 4
To display the number of MP3 files , .txt files present in a directory
$ ls ~/Music | grep -c .mp3
$ ls /home/ilugc | grep -c .txt
regards,
T.Dhanasekar