FreeSWITCH supplies a tool that offers a simplified means of creating interactive scripts. Unlike the socket application presented in Using the ESL connection object for call control in this chapter, using fs_ivrd relieves the programmer from having to maintain socket connections and handle child processes. The fs_ivrd tool provides a simple interface using the STDIN and STDOUT file handles. The example Perl script presented here uses the ESL::IVR Perl module supplied with ESL. As of this writing there had not been any other fs_ivrd modules written for any of the other scripting languages.
This example requires that the ESL Perl module be properly compiled. See Setting up the event socket library earlier in this chapter. Also, it is helpful to have at least two terminal windows open so that you can view the script as well as fs_cli. Note: fs_ivrd is not supported in Windows environments.