Needed wrapper unit tests

[CamStan]

This ticket is for listing any unit tests that need to be implemented for individual wrappers in client/src. If a suggested test revolves around a bigger issue, create a separate issue and link to it from here.

Place each suggested test in a separate comment.

For each suggested test, identify which wrapped call(s) it would make the most sense to test under (i.e., open, open64, fread, fseek, etc).

[CamStan]

read, readv, pread, pread64, fread

We might want to come up with a test that opens two distinct file descriptors to the same file, e.g., for reading at different points in the file. Reading from one should not affect the other. This could potentially be two tests, one (possible in open, open64, fopen) for making sure we can open two distinct file descriptors, and one in the ensuring the reads don't affect one another.