Although one of the primary design concepts of the FITSH package was to provide a robust set of command-line driven utilities and to provide a shell-hosted environment for massive batched image processing; the individual FITSH tasks can be exploited easily to create interactive applications as well. In this example we show how the tasks firandom, fiphot and lfit can be used to implement the well-known IRAF task, imexamine (that is usually referred as simply as imexam, see also this or this references).
Indeed, FITSH does not provide any tool for plotting, so displaying the respective graphs and plots expected from this imexam scriptlet; we have to use some third-party tool for this purpose. In our example here, we employ one of the most popular free graphing utility, gnuplot. Similarly to the original IRAF-hosted implementation, this imexam scriptlet exploits the built-in features of the astronomical visualization application DS9 and uses the XPA messaging interface in order to establish communication between the scriptlet and DS9. Therefore, this program expects all of the above utilities installed and properly configured on your system. In addition, this example needs also some awk implementation as well.