[DISK] Add shard option to disk

src/common/common.h

@@ -0,0 +1,31 @@
+/*!
+ * Copyright 2015 by Contributors
+ * \file common.h
+ * \brief Common utilities
+ */
+#ifndef XGBOOST_COMMON_COMMON_H_
+#define XGBOOST_COMMON_COMMON_H_
+
+#include <vector>
+#include <string>
+#include <sstream>
+
+namespace xgboost {
+namespace common {
+/*!
+ * \brief Split a string by delimiter
+ * \param s String to be splitted.
+ * \param delim The delimiter.
+ */
+inline std::vector<std::string> Split(const std::string& s, char delim) {
+  std::string item;
+  std::istringstream is(s);
+  std::vector<std::string> ret;
+  while (std::getline(is, item, delim)) {
+    ret.push_back(item);
+  }
+  return ret;
+}
+}  // namespace common
+}  // namespace xgboost
+#endif  // XGBOOST_COMMON_COMMON_H_