Learning Linux Shell Scripting - Second Edition

Creating a library of functions

If we want to create our own library of functions, then we can create a script and add all the functions into this script. We can make all the functions from our script functions.sh available in the current shell by calling source or the period . command.

The procedure to load all functions into the current shell is as follows:

    $ country USA
  

Since the country function is not a part of the shell environment, this command will give an error:

    $ . functions.sh
  

Or it could display this one:

    $ source functions.sh
    $ country USA India Japan
  

This will execute the country function along with the parameter, USA India Japan.

We can even load a script containing library functions inside another script as follows: ...