More file split

util.cc

@@ -0,0 +1,31 @@
+#include "util.h"
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <cassert>
+
+std::string ReadFile(const std::string& filename) {
+  int fh = open(filename.c_str(), O_RDONLY);
+  assert(fh != -1);
+
+  struct stat st;
+  assert(fstat(fh, &st) == 0);
+  
+  std::string contents;
+  contents.resize(static_cast<size_t>(st.st_size));
+
+  assert(read(fh, &contents[0], static_cast<size_t>(st.st_size)) == st.st_size);
+  assert(close(fh) == 0);
+
+  return contents;
+}
+
+void WriteFile(const std::string& filename, const std::string& contents) {
+  int fh = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);
+  assert(fh != -1);
+  assert(write(fh, &contents[0], contents.size()) == static_cast<ssize_t>(contents.size()));
+  assert(close(fh) == 0);
+}