write/read,recv/send, recvfrom/sendto,,recvmsg/sendmsg的区别
write/readssize_twrite(intfd,constvoid*buf,size_tcount);ssize_tread(intfd,void*buf,size_tcount);write()会把参数buf所指的内存写入count个字节到参数放到所指的文件/缓冲区内,即将用户缓冲区当中的内容放入到内核缓冲区(socket缓冲区)当中。当内核缓冲区已满时,write函数会阻塞。read