Chapter 57 Unix Domain Sockets

Objectives

1. Look at unix domain sockets.

Notes

• Addresses in AF_UNIX are file paths.
• For AF_UNIX the path is around 100 bytes.
• Permissions on this path apply.
• While they look like files, they are not.
  • You can not open/close a socket path.
• The path name can not exist at bind.
  • unlink(const char * pathname) command
  • Could check for ENOENT - file does not exist.
• memset assures that all fields are cleared.
• message sizes should be limited to 2048 bytes for portability
• There is a system call (socketpair) that functions like pipe
  • Common ancestor.