Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
The ImageMagick command line does not directly support an indirect command line reference but some options do and you can wildcard the image filenames. For example,
I think you should be able to put all your command line arguments in a file and write a script that would read the file and put all the text into a string variable and then have the IM command reference the string variable,
The script does not help, since the bash resolves the variable-reference and you are still left with a commandline which could be just too long. In fact, my very long commandline is generated that way.
Is is possible that a future version of IM could support reading the commandline from a file? In fact, IM is more like a programming-language, so why shouldn't it read it's program from a file?
Note that ImageMagick can be called from a number of scripting languages right now: Perl, PHP, Ruby, etc. As you rightly point out, very long ImageMagick commands lines are very nearly as complicated as a program anyway. Instead of struggling with command shells, why not make the jump to a full-fledged programming language?
I have an image-processing system with 6700+ lines of bash-code. So the jump to a full-fledged programming language is not that easy. Anyhow, the current versions of bash _is_ a full-fledged programming language (well, almost).
There are certainly more important topics for IM to work on, but maybe you can put the issue on the long-run wish-list.