Learning Linux Shell Scripting - Second Edition

The here string and the <<< operator

The here string is used for input redirection from <indexentry content="<<text or a variable. Input is mentioned on the same line within single quotes ('').

The syntax is as follows:

    $ command <<< 'string'
  

1. Let's see the following example, hereString_01.sh:

#!/bin/bash 
wc -w <<< 'Good Morning and have a nice day !' 

2. Save the file, give the permission, and run the script as follows:

    $ chmod u+x hereString_01.sh
    $ ./hereString_01.sh
  

3. Here is the output:

    8
  

In this example, the string Good Morning and have a nice day ! is called as the here string.