Also the very arcane nature of their syntax!

The awk language isn't too bad, being somewhat C-like. Sed, on the other hand, is much worse, but that does not stop me from using it when it appears to be the right tool. I think the languages like Perl and Python are somewhat better regarding syntax and structure, but I haven't had the time to learn them.

(probably attirubutable [sic] to their UNIX heritage?)

No doubt. Text processing languages of this type have an arcane nature that is mostly attributable to the regular expression syntax and not so much related to the other features of the language. For that matter, most (decent) programmer's editors support regular expressions and use similar arcane syntax. That kind of editor would have performed the original poster's task with a single regex replace, thus eliminating the need for a separate C program or language script.

The real intent of my posts in this thread was to encourage folks to think outside the Asm/C box (if you only have a hammer, everything looks like a nail). There are a whole bunch of free tools available that are tailored to specific types of problems. For dealing with a text processing problems, if my editor can't do it without a lot of manual coercion, or if the task will need to be performed repetitively (let's say as part of a build or debug toolchain), writing a tool in C would not be my first choice.