- Let us create a file and add a few entries to it
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
$ # add some data to a file
$ echo "123\n456\nabc\ndef\nghi\n" > test.txt
$ # view the file contents
$ cat test.txt
123
456
abc
def
ghi
$ # search for 123 using grep
$ grep '123' test.txt
123
$ # search for ghi using grep
$ grep 'ghi' test.txt
ghi
Now what if we want to search for multiple entries at the same time
We want grep to search for 123 or def or 456, in this case:
The or operator in grep is \|
So the search string will look like
abc\|def\|456
1
2
3
4
$ grep 'abc\\|def\\|456' test.txt
456
abc
def