Changes to make it a little more robust

diff --git a/demo/cmd.c b/demo/cmd.c
index 9c3f2532a906ae504fa9a2a937ba97aa14f12e91..82c3f3655f137424543224a3cc4269f75b6e30b3 100644 (file)
--- a/demo/cmd.c
+++ b/demo/cmd.c
@@ -85,8 +85,8 @@ int main(int argc, char *argv[])
        /* prepare_cmd_lib() uses a Comedilib routine to find a
         * good command for the device.  prepare_cmd() explicitly
         * creates a command, which may not work for your device. */
-       //prepare_cmd_lib(dev,subdevice,cmd);
-       prepare_cmd(dev,subdevice,cmd);
+       prepare_cmd_lib(dev,subdevice,cmd);
+       //prepare_cmd(dev,subdevice,cmd);
        
        fprintf(stderr,"command before testing:\n");
        dump_cmd(stderr,cmd);
@@ -126,6 +126,10 @@ int main(int argc, char *argv[])
                exit(1);
        }
 
+       /* this is only for informational purposes */
+       gettimeofday(&start,NULL);
+       fprintf(stderr,"start time: %ld.%06ld\n",start.tv_sec,start.tv_usec);
+
        /* start the command */
        ret=comedi_command(dev,cmd);
        if(ret<0){
@@ -133,10 +137,6 @@ int main(int argc, char *argv[])
                exit(1);
        }
 
-       /* this is only for informational purposes */
-       gettimeofday(&start,NULL);
-       fprintf(stderr,"start time: %ld.%06ld\n",start.tv_sec,start.tv_usec);
-
        while(1){
                ret=read(comedi_fileno(dev),buf,BUFSZ);
                if(ret<0){
@@ -184,11 +184,16 @@ int prepare_cmd_lib(comedi_t *dev,int subdevice,comedi_cmd *cmd)
 {
        int ret;
 
+       memset(cmd,0,sizeof(*cmd));
+
        /* This comedilib function will get us a generic timed
         * command for a particular board.  If it returns -1,
         * that's bad. */
        ret = comedi_get_cmd_generic_timed(dev,subdevice,cmd,1e9/freq);
-       if(ret<0)return ret;
+       if(ret<0){
+               printf("comedi_get_cmd_generic_timed failed\n");
+               return ret;
+       }
 
        /* Modify parts of the command */
        cmd->chanlist           = chanlist;