How do you discover system builtins for C functions? The man pages for the C functions on Linux are great, but only if you know the name of the function. Is there a way to see a detailed table of contents, or to browse Manpages on a Linux distro?
ls /usr/share/man/man?/* will show you all the man pages on your system. I used to pick ones at random.
Originally there were a number of manuals. Manual 1 had user commands. Manual 2 had system calls. Etc. You can type man NUMBER intro to read about that manual. You can also use man -k or appropos but I've also just used grep. These days they're compressed so zgrep.
On Archlinux at least, the glibc package includes info pages for C functions. Just type info libc at the command line, or use info inside emacs. There are hyperlinks in info pages, it's a nicer interface than man pages.
On Debian, there is a package that displays system documentation including, if I remember correctly, man pages. I think I had to set up a local web server first.