Replace system("uname -a") with call to uname(3).

Slightly reworked version of a patch that was...

Submitted by:	Susant Sahani <ssahani@redhat.com>

src/iperf_api.c

@@ -588,8 +588,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
                 test->json_output = 1;
                 break;
             case 'v':
-                printf("%s\n", version);
-		system("uname -a");
+                printf("%s\n%s\n", version, get_system_info());
                 exit(0);
             case 's':
                 if (test->role == 'c') {

src/iperf_client_api.c

@@ -356,7 +356,7 @@ iperf_run_client(struct iperf_test * test)
 	iprintf(test, "%s\n", version);
 	iprintf(test, "%s", "");
 	fflush(stdout);
-	system("uname -a");
+	printf("%s\n", get_system_info());
     }
 
     /* Start the client and connect to the server */

src/iperf_server_api.c

@@ -450,7 +450,7 @@ iperf_run_server(struct iperf_test *test)
 	iprintf(test, "%s\n", version);
 	iprintf(test, "%s", "");
 	fflush(stdout);
-	system("uname -a");
+	printf("%s\n", get_system_info());
     }
 
     // Open socket and listen

src/iperf_util.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2011, The Regents of the University of California,
+ * Copyright (c) 2009-2014, The Regents of the University of California,
  * through Lawrence Berkeley National Laboratory (subject to receipt of any
  * required approvals from the U.S. Dept. of Energy).  All rights reserved.
  *
@@ -22,6 +22,7 @@
 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include <sys/utsname.h>
 #include <time.h>
 #include <errno.h>
 
@@ -193,19 +194,20 @@ cpu_util(double pcpu[3])
     pcpu[2] = (systemdiff / timediff) * 100;
 }
 
-char*
+char *
 get_system_info(void)
-    {
-    FILE* fp;
-    static char buf[1000];
+{
+    static char buf[1024];
+    struct utsname  uts;
+
+    memset(buf, 0, 1024);
+    uname(&uts);
+
+    snprintf(buf, sizeof(buf), "%s %s %s %s %s", uts.sysname, uts.nodename, 
+	     uts.release, uts.version, uts.machine);
 
-    fp = popen("uname -a", "r");
-    if (fp == NULL)
-	return NULL;
-    fgets(buf, sizeof(buf), fp);
-    pclose(fp);
     return buf;
-    }
+}
 
 
 /* Helper routine for building cJSON objects in a printf-like manner.