SIGPIPE
I was changing a send call to a writev and ran into an annoying problem. On the send call I had set the MSG_NOSIGNAL flag to stop any SIGPIPE signals if the socket I was writing to was closed, unfortunately I cannot set the same flag on writev! (I had originally switched from using write to send to be able to set the flag) On some systems (BSD) you can set the socket option SO_NOSIGPIPE to get a similar effect, but on Linux it doesn't look like this option is supported. The other option is to set the system to ignore a SIGPIPE, but there are issues with this if you do it naively, see Suppressing SIGPIPE in a library.