[Utils] Add three rare to find convenience functions.

src/XrdOuc/XrdOucProg.cc

@@ -161,6 +161,29 @@ int XrdOucProg::Run(XrdOucStream *Sp, const char *argV[], int argC,
    return 0;
 }
 
+/******************************************************************************/
+
+int XrdOucProg::Run(const char *argV[], int argC, const char *envV[])
+{
+   XrdOucStream cmd;
+   char *lp;
+   int rc;
+
+// Execute the command
+//
+   rc = Run(&cmd, argV, argC, envV);
+   if (rc) return rc;
+
+// Drain all output
+//
+   while((lp = cmd.GetLine()))
+        if (eDest && *lp) eDest->Emsg("Run", lp);
+
+// All done
+//
+   return RunDone(cmd);
+}
+
 /******************************************************************************/
 
 int XrdOucProg::Run(XrdOucStream *Sp, const char *arg1, const char *arg2,

src/XrdOuc/XrdOucProg.hh

@@ -71,9 +71,12 @@ XrdOucStream *getStream() {return myStream;}
 // additional arguments to be appended to the existing ones. The
 // method also allows envars to be set in forked process via envV vector
 // which contains strings "var=val" and terminaes with a null pointer.
+// When using the form without a stream pointer, command output is thrown away.
 //
-int         Run(XrdOucStream *Sp, const char *argV[], int argc=0,
-                                  const char *envV[]=0);
+int          Run(XrdOucStream *Sp, const char *argV[], int argc=0,
+                                   const char *envV[]=0);
+
+int          Run(const char *argV[], int argC, const char *envV[]=0);
 
 // Run executes the command that was passed via Setup(). You may pass
 // up to four additional arguments that will be added to the end of any