make select() watch for errors

git-svn-id: https://hamlib.svn.sourceforge.net/svnroot/hamlib/trunk@2427 7ae35d74-ebe9-4afe-98af-79ac388436b8

src/iofunc.c

@@ -2,7 +2,7 @@
  *  Hamlib Interface - generic file based io functions
  *  Copyright (c) 2000-2008 by Stephane Fillod and Frank Singleton
  *
- *	$Id: iofunc.c,v 1.18 2008-10-26 10:47:33 fillods Exp $
+ *	$Id: iofunc.c,v 1.19 2008-10-27 22:20:21 fillods Exp $
  *
  *   This library is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Library General Public License as
@@ -170,13 +170,11 @@ int HAMLIB_API write_block(hamlib_port_t *p, const char *txbuffer, size_t count)
 
 int HAMLIB_API read_block(hamlib_port_t *p, char *rxbuffer, size_t count)
 {  
-  fd_set rfds;
+  fd_set rfds, efds;
   struct timeval tv, tv_timeout;
   int rd_count, total_count = 0;
   int retval;
 
-  FD_ZERO(&rfds);
-  FD_SET(p->fd, &rfds);
 
   /*
    * Wait up to timeout ms.
@@ -187,7 +185,11 @@ int HAMLIB_API read_block(hamlib_port_t *p, char *rxbuffer, size_t count)
   while (count > 0) {
 	tv = tv_timeout;	/* select may have updated it */
 
-		retval = select(p->fd+1, &rfds, NULL, NULL, &tv);
+	FD_ZERO(&rfds);
+	FD_SET(p->fd, &rfds);
+	efds = rfds;
+
+	retval = select(p->fd+1, &rfds, NULL, &efds, &tv);
 	if (retval == 0) {
 		dump_hex((unsigned char *) rxbuffer, total_count);
 		rig_debug(RIG_DEBUG_WARN, "read_block: timedout after %d chars\n",
@@ -200,6 +202,11 @@ int HAMLIB_API read_block(hamlib_port_t *p, char *rxbuffer, size_t count)
 						"%s\n", total_count, strerror(errno));
 		return -RIG_EIO;
 	}
+	if (FD_ISSET(p->fd, &efds)) {
+		rig_debug(RIG_DEBUG_ERR, "%s: fd error after %d chars\n", 
+                                  __FUNCTION__, total_count);
+		return -RIG_EIO;
+	}
 
 	/*
 	 * grab bytes from the rig
@@ -249,14 +256,11 @@ int HAMLIB_API read_block(hamlib_port_t *p, char *rxbuffer, size_t count)
 int HAMLIB_API read_string(hamlib_port_t *p, char *rxbuffer, size_t rxmax, const char *stopset,
 				int stopset_len)
 {
-  fd_set rfds;
+  fd_set rfds, efds;
   struct timeval tv, tv_timeout;
   int rd_count, total_count = 0;
   int retval;
 
-  FD_ZERO(&rfds);
-  FD_SET(p->fd, &rfds);
-
   /*
    * Wait up to timeout ms.
    */
@@ -266,7 +270,11 @@ int HAMLIB_API read_string(hamlib_port_t *p, char *rxbuffer, size_t rxmax, const
   while (total_count < rxmax-1) {
 	tv = tv_timeout;	/* select may have updated it */
 
-		retval = select(p->fd+1, &rfds, NULL, NULL, &tv);
+	FD_ZERO(&rfds);
+	FD_SET(p->fd, &rfds);
+	efds = rfds;
+
+	retval = select(p->fd+1, &rfds, NULL, &efds, &tv);
         if (retval == 0)    /* Timed out */
             break;
 
@@ -276,6 +284,13 @@ int HAMLIB_API read_string(hamlib_port_t *p, char *rxbuffer, size_t rxmax, const
                                   __FUNCTION__, total_count, strerror(errno));
 		return -RIG_EIO;
 	}
+
+	if (FD_ISSET(p->fd, &efds)) {
+		rig_debug(RIG_DEBUG_ERR, "%s: fd error after %d chars\n", 
+                                  __FUNCTION__, total_count);
+		return -RIG_EIO;
+	}
+
 	/*
        	 * read 1 character from the rig, (check if in stop set)
 	 * The file descriptor must have been set up non blocking.