The libc is certainly not a good guide:

    * Buffer overruns are not ruled out by design: gets, sscanf etc.
    * Interface inconsistencies: gets vs fgets, fgets vs fscanf (note
    the position of the file stream parameter)
    * Bad interfaces like that of getchar() whose return code
    can be a character or an error code
    * Particularly bad buffering system which
    – ignores the block structure of underlying file systems, and
    – does not support bidirectional buffering
    * No provisions exist such that independent libraries can cooperate
    with each other in
    – signal handling,
    – setting up alarms, and
    – tracking childs.

    (Please note that I do not want to bash Ritchie, Kernighan etc. The
    libc is history and should be taken as such… It is time to abandon
    C and the libc and it does not help to place other systems on top of this historic relic.)