Added ssh_channel_write_stderr() for the server

include/libssh/server.h

@@ -199,6 +199,9 @@ LIBSSH_API int ssh_channel_request_send_exit_signal(ssh_channel channel,
                                                 int core,
                                                 const char *errmsg,
                                                 const char *lang);
+LIBSSH_API int ssh_channel_write_stderr(ssh_channel channel,
+                                                const void *data,
+                                                uint32_t len);
 
 /* deprecated functions */
 SSH_DEPRECATED LIBSSH_API int ssh_accept(ssh_session session);

src/channels.c

@@ -2595,6 +2595,23 @@ int ssh_channel_select(ssh_channel *readchans, ssh_channel *writechans,
 }
 
 #if WITH_SERVER
+/**
+ * @brief Blocking write on a channel stderr.
+ *
+ * @param[in]  channel  The channel to write to.
+ *
+ * @param[in]  data     A pointer to the data to write.
+ *
+ * @param[in]  len      The length of the buffer to write to.
+ *
+ * @return              The number of bytes written, SSH_ERROR on error.
+ *
+ * @see channel_read()
+ */
+int ssh_channel_write_stderr(ssh_channel channel, const void *data, uint32_t len) {
+  return channel_write_common(channel, data, len, 1);
+}
+
 /**
  * @brief Open a TCP/IP reverse forwarding channel.
  *