Add support for iocsh 'system' command.

src/iocsh/Makefile

@@ -49,6 +49,7 @@ LIBSRCS += asTestRegister.c
 LIBSRCS += envRegister.c
 LIBSRCS += iocUtil.c
 LIBSRCS += iocCoreLimitsRegister.c
+LIBSRCS += systemCommandRegister.c
 LIBSRCS += registryRegister.c
 
 LIBRARY_IOC = iocsh

src/iocsh/systemCommandRegister.c

@@ -0,0 +1,39 @@
+/*************************************************************************\
+* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
+*     National Laboratory.
+* Copyright (c) 2002 The Regents of the University of California, as
+*     Operator of Los Alamos National Laboratory.
+* EPICS BASE Versions 3.13.7
+* and higher are distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution. 
+\*************************************************************************/
+/*
+ * Escape to system command interpreter.  To enable this command, add
+ *      registrar(iocshSystemCommand)
+ * to an application dbd file.
+ *
+ * $Id$
+ */
+#include <stdlib.h>
+#include <errlog.h>
+#include <iocsh.h>
+#include <epicsExport.h>
+
+/* system */
+static const iocshArg systemArg0 = { "command string",iocshArgString};
+static const iocshArg * const systemArgs[1] = {&systemArg0};
+static const iocshFuncDef systemFuncDef = {"system",1,systemArgs};
+static void systemCallFunc(const iocshArgBuf *args)
+{
+    system(args[0].sval);
+}
+
+static void
+iocshSystemCommand(void)
+{
+    if (system(NULL))
+        iocshRegister(&systemFuncDef,systemCallFunc);
+    else
+        errlogPrintf ("Can't register 'system' command -- no command interpreter available.\n");
+}
+epicsExportRegistrar(iocshSystemCommand);