Add iocshArgPersistentString type.

src/iocsh/iocsh.cpp

@@ -21,6 +21,7 @@
 
 #include "errlog.h"
 #include "dbAccess.h"
+#include "epicsString.h"
 #include "epicsThread.h"
 #include "epicsMutex.h"
 #include "registry.h"
@@ -179,6 +180,10 @@ cvtArg (const char *filename, int lineno, char *arg, iocshArgBuf *argBuf, const
         argBuf->sval = arg;
         break;
 
+    case iocshArgPersistentString:
+        argBuf->sval = epicsStrDup(arg);
+        break;
+
     case iocshArgPdbbase:
         /* Argument must be missing or 0 or pdbbase */
         if(!arg || !*arg || (*arg == '0') || (strcmp(arg, "pdbbase") == 0)) {

src/iocsh/iocsh.h

@@ -25,7 +25,8 @@ typedef enum {
     iocshArgDouble,
     iocshArgString,
     iocshArgPdbbase,
-    iocshArgArgv
+    iocshArgArgv,
+    iocshArgPersistentString
 }iocshArgType;
 
 typedef union iocshArgBuf {