From 90425b93fce135c3764225f4fd313f730f873a19 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Fri, 8 Jan 2016 22:02:23 +0100 Subject: [PATCH] recv.2: Equivalence to read Describe the recv(2)-read(2) and the recvfrom(2)-recv(2) equivalences for zero-valued arguments. Signed-off-by: Heinrich Schuchardt Signed-off-by: Michael Kerrisk --- man2/recv.2 | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/man2/recv.2 b/man2/recv.2 index 84bd0770d..33265b8e0 100644 --- a/man2/recv.2 +++ b/man2/recv.2 @@ -68,6 +68,26 @@ to receive data on both connectionless and connection-oriented sockets. This page first describes common features of all three system calls, and then describes the differences between the calls. .PP +The only difference between +.BR recv () +and +.BR read (2) +is the presence of +.IR flags . +With a zero +.I flags +argument, +.BR recv () +is equivalent to +.BR read (2). +Also, the following call + + recv(sockfd, buf, len, flags); + +is equivalent to + + recvfrom(sockfd, buf, len, flags, NULL, NULL); +.PP All three calls return the length of the message on successful completion. If a message is too long to fit in the supplied buffer, excess