title: Is seteuid a system call on Linux?
body: <p>All of the literature that I have read so far on <code>setuid</code> talks about <code>seteuid</code> in a way that implies it is a system call. The section 2 <code>man</code> pages never say if a function is a system call or not, so <code>seteuid(2)</code> is no help. And if it isn't a system call, meaning the functionality is not provided by the kernel, then how can "set effective UID" be achieved?</p>