Fred seems to be an Imagemagick Expert who has written a lot of free shellscripts, over the years.
There are examples of multiline scripts for complex tasks (e.g. improving bad (greyed, inclined) scans or prints from a copymachine). Scroll down for illustrations, its a rather long webpage.
# Licensing:
#
# Copyright © Fred Weinhaus
#
# My scripts are available free of charge for non-commercial use, ONLY.
#
# For use of my scripts in commercial (for-profit) environments or
# non-free applications, please contact me (Fred Weinhaus) for
# licensing arrangements. My email address is fmw at alink dot net.
#
# If you: 1) redistribute, 2) incorporate any of these scripts into other
# free applications or 3) reprogram them in another scripting language,
# then you must contact me for permission, especially if the result might
# be used in a commercial or for-profit environment.
#
# My scripts are also subject, in a subordinate manner, to the ImageMagick
# license, which can be found at: http://www.imagemagick.org/script/license.php