Design Notes

These design notes may be useful to people interested in the source code.

• Default bytes per line and lines per page are stored as constants so they may be changed more easily
• Most of the program code is contained within the HexDump () function, leaving only the command-line argument parsing to the main () function. This makes the program easier to be re-used in another program
• The code that provides the editor feature is only compiled when the pre-processor definition INCLUDE_EDITOR is defined. This makes it possible to compile a smaller version of the program that doesn’t include the editor. On my compiler, the executable without editing support is 172 KB and with editing support is 176 KB (this is using the static run-time library with debug information included). 4 KB is not much, but this demonstrates conditional compilation
• The stdafx.h file is included in place of stdio.h, stdlib.h and string.h. Stdafx.h is a file that Visual C++ (the compiler I use at home) sets up automatically when creating a new program with the recommendation that other header files are included there. I am assuming this is to speed up compilation as the headers are only compiled once and simply re-linked each time the program code changes.
• Stdafx.h can be replaced by stdio.h, stdlib.h and string.h and the program should still run (although a few changes to project settings may be required)
• When displaying a file, offsets are shown in hexadecimal by default, but this can be changed to decimal using a command line argument