[fffggg]

That's incorrect. As was already pointed out this issue has nothing to do with reading data from the filesystem or manipulating variables internal to the program and everything to do with poor choices made when using printf.

In other words, those files aren't causing the QEMU program internals to re-interpolate one variable as two values. They're merely messing up a poorly written data exchange format.

Other languages such as I listed above simply do not have the same issue. The C program did not mis-interpret a variable as two separate values because it contained spaces. That is the nature of the danger with shell -- any reference to a variable in Bourne involves string interpolation and tokenization. This simply does not happen in C.