ssize_t pread(int fd, void *buffer, size_t count, off_t offset); ssize_t pwrite(int fd, void *buffer, size_t count, off_t offset);
These syscalls do the same as read and write respectively, but
instead of using the description’s saved location for data access, they use the
passed offset, and do not update it at the end of the operation.
fd must point to a seekable file.
These syscalls are made for use in multithreaded applications, as having more than one thread updating file locations for a shared file description can lead to sudden catharsis.
These syscalls return the same values and errno as the non-p variants. read/write.