FSSH_SEEK_CUR
#define SEEK_CUR FSSH_SEEK_CUR
#ifndef FSSH_SEEK_CUR
case FSSH_SEEK_CUR:
case FSSH_SEEK_CUR:
fssh_ssize_t bytesRead = _kern_read(fd, fssh_lseek(fd, 0, FSSH_SEEK_CUR),
fssh_lseek(fd, bytesRead, FSSH_SEEK_CUR);
fssh_ssize_t written = write_pos(fd, fssh_lseek(fd, 0, FSSH_SEEK_CUR),
fssh_lseek(fd, written, FSSH_SEEK_CUR);
case FSSH_SEEK_CUR:
case FSSH_SEEK_CUR: