From c3849ed9f9f39ea0ad5dfe2c28568cd495ebdb00 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Sun, 15 Aug 2021 19:58:15 +0200
Subject: [PATCH] sock: tcp: fix sock_tcp_read() example

sock_tcp_read() will return 0 if the connection was closed, we
need to check for this.
---
 sys/include/net/sock/tcp.h | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/sys/include/net/sock/tcp.h b/sys/include/net/sock/tcp.h
index 5766942dc7d6..eb9bfc5b2b73 100644
--- a/sys/include/net/sock/tcp.h
+++ b/sys/include/net/sock/tcp.h
@@ -55,7 +55,7 @@
  *             while (read_res >= 0) {
  *                 read_res = sock_tcp_read(sock, &buf, sizeof(buf),
  *                                          SOCK_NO_TIMEOUT);
- *                 if (read_res < 0) {
+ *                 if (read_res <= 0) {
  *                     puts("Disconnected");
  *                     break;
  *                 }
@@ -153,7 +153,7 @@
  *             while (read_res >= 0) {
  *                 read_res = sock_tcp_read(sock, &buf, sizeof(buf),
  *                                          SOCK_NO_TIMEOUT);
- *                 if (read_res < 0) {
+ *                 if (read_res <= 0) {
  *                     puts("Disconnected");
  *                     break;
  *                 }
@@ -216,7 +216,7 @@
  *     }
  *     else {
  *         if ((res = sock_tcp_read(&sock, &buf, sizeof(buf),
- *                                  SOCK_NO_TIMEOUT)) < 0) {
+ *                                  SOCK_NO_TIMEOUT)) <= 0) {
  *             puts("Disconnected");
  *         }
  *         printf("Read: \"");
@@ -271,7 +271,7 @@
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.c}
  *     else {
  *         if ((res = sock_tcp_read(&sock, &buf, sizeof(buf),
- *                                  SOCK_NO_TIMEOUT)) < 0) {
+ *                                  SOCK_NO_TIMEOUT)) <= 0) {
  *             puts("Disconnected");
  *         }
  *         printf("Read: \"");
@@ -505,7 +505,8 @@ int sock_tcp_accept(sock_tcp_queue_t *queue, sock_tcp_t **sock,
  * @note    Function may block.
  *
  * @return  The number of bytes read on success.
- * @return  0, if no read data is available, but everything is in order.
+ * @return  0, if no read data is available or the connection was orderly closed
+ *          by the remote host.
  * @return  -EAGAIN, if @p timeout is `0` and no data is available.
  * @return  -ECONNABORTED, if the connection is aborted while waiting for the
  *          next data.