UNIX System Call Listing?
There's also a useful utility called "apropos"
$ whatis aproposapropos (1) - search the manual page names and descriptions$ apropos filename...fnmatch (3) - match filename or pathname...
System calls are documented in section 2 of the man documentation. Depending on your version of Unix, you should be able to find these pages in the man data directory.
On Linux, this directory is /usr/share/man/man2; your version of Unix may differ. Also man man should tell you what is in the other sections.
I used to keep a printed copy of part of "The Authorized Guide to Version 3 of the Single UNIX Specification" lying around - the table shows availability of calls in a variety of different standards, which was extremely useful for supporting multiple targets.