I would like to understand the term "system call". I am familiar that system calls are used to get kernel services from a userspace application. The part i need clarification with is the difference ...
As we know, the C standard does not specify a lot of details of the implementation, for example value of NULL pointer, order of bits and bytes (endiannes), alignment in structs and of stack ...
I see that pid_t is typedef'd in unistd.h, and file descriptors are defined to be int in fcntl.h. But since they are used in similar ways, wouldn't it make sense to have a typedef for file ...