Agreed, I think it was just a matter of being originally developed at a time when memory was tight and CPU cycles were few. That is, if the original UNIX were d

Agreed, I think it was just a matter of being originally developed at a time when memory was tight and CPU cycles were few. That is, if the original UNIX were developed today with otherwise the same development culture, I'm not sure that we'd see fixed length restrictions. One of GNU's original goals was eliminating arbitrary fixed size limits in UNIX tools, in exchange for using more memory. It's discussed in https://www.gnu.org/gnu/thegnuproject.en.html https://www.gnu.org/gnu/thegnuproject.en.html under "Technical goals". > But it was natural to apply the known standards of good practice to the work—for example, dynamically allocating data structures to avoid arbitrary fixed size limits, and handling all the possible 8-bit codes wherever that made sense. > In addition, we rejected the Unix focus on small memory size, by deciding not to support 16-bit machines (it was clear that 32-bit machines would be the norm by the time the GNU system was finished), and to make no effort to reduce memory usage unless it exceeded a megabyte.