Regex to look for multiple characters or words in linux bash shell ?
Today we will look at the regex to search/grep multiple characters or words from a file or output in linux.
First create a file with below contents.
[root@nglinux ]# cat testfile hello welcome to ngelinux first line second line [root@nglinux ]#
Now lets see how to search for multiple characters or words.
1. Multiple characters
### Search for NGe and hence no result.
[root@nglinux ~]# echo "Welcome to NGELinux" | awk '/NGe/{print $0}'
### Search for NG and third character in either e or E.
[root@nglinux ~]# echo "Welcome to NGELinux" | awk '/NG[eE]/{print $0}'
Welcome to NGELinux
2. Multiple words
### Search for one word
[root@nglinux ]# cat testfile | awk '/line/{print $0}'
first line
second line
### Search for two words
[root@nglinux ]# cat testfile | awk '/line|hello/{print $0}'
hello
first line
second line
[root@nglinux ]#
### Search for three different words
[root@nglinux ]# cat testfile | awk '/line|hello|welcome/{print $0}'
hello
welcome to ngelinux
first line
second line
In the similar fashion above, you can search for multiple words or characters on Linux shell.