diff --git a/delta_diff_generator_unittest.cc b/delta_diff_generator_unittest.cc
index 1a963da..6d989a1 100644
--- a/delta_diff_generator_unittest.cc
+++ b/delta_diff_generator_unittest.cc
@@ -427,7 +427,7 @@
                                                    new_blobs));
 
   string new_data;
-  EXPECT_TRUE(utils::ReadFileToString(new_blobs, &new_data));
+  EXPECT_TRUE(utils::ReadFile(new_blobs, &new_data));
   EXPECT_EQ("bcda", new_data);
   EXPECT_EQ(2, manifest.install_operations_size());
   EXPECT_EQ(0, manifest.install_operations(0).data_offset());
diff --git a/integration_unittest.cc b/integration_unittest.cc
index 4c43b35..f42b89e 100644
--- a/integration_unittest.cc
+++ b/integration_unittest.cc
@@ -56,7 +56,8 @@
     if (action->Type() == InstallAction::StaticType()) {
       InstallAction* install_action = static_cast<InstallAction*>(action);
       old_dev_ = install_action->GetOutputObject();
-      string dev = BindToUnusedDevice(kTestDir + "/dev2");
+      string dev;
+      BindToUnusedDevice(kTestDir + "/dev2", &dev);
       install_action->SetOutputObject(dev);
     } else if (action->Type() == PostinstallRunnerAction::StaticType()) {
       PostinstallRunnerAction* postinstall_runner_action =
@@ -178,7 +179,7 @@
   ASSERT_EQ(0, lstat("/tmp/update_engine_test_postinst_out.txt", &stbuf));
   EXPECT_TRUE(S_ISREG(stbuf.st_mode));
   string file_data;
-  EXPECT_TRUE(utils::ReadFileToString(
+  EXPECT_TRUE(utils::ReadFile(
       "/tmp/update_engine_test_postinst_out.txt",
       &file_data));
   EXPECT_EQ("POSTINST_DONE\n", file_data);
diff --git a/omaha_request_params.cc b/omaha_request_params.cc
index 3733f10..e240c86 100644
--- a/omaha_request_params.cc
+++ b/omaha_request_params.cc
@@ -147,7 +147,7 @@
     // TODO(adlr): make sure files checked are owned as root (and all their
     // parents are recursively, too).
     string file_data;
-    if (!utils::ReadFileToString(root_ + *it, &file_data))
+    if (!utils::ReadFile(root_ + *it, &file_data))
       continue;
 
     map<string, string> data = simple_key_value_store::ParseString(file_data);
diff --git a/omaha_request_params_unittest.cc b/omaha_request_params_unittest.cc
index 090c514..ecaa682 100644
--- a/omaha_request_params_unittest.cc
+++ b/omaha_request_params_unittest.cc
@@ -55,22 +55,14 @@
 
 namespace {
 string GetMachineType() {
-  FILE* fp = popen("uname -m", "r");
-  if (!fp)
+  string machine_type;
+  if (!utils::ReadPipe("uname -m", &machine_type))
     return "";
-  string ret;
-  for (;;) {
-    char buffer[10];
-    size_t r = fread(buffer, 1, sizeof(buffer), fp);
-    if (r == 0)
-      break;
-    ret.insert(ret.begin(), buffer, buffer + r);
-  }
-  // strip trailing '\n' if it exists
-  if ((*ret.rbegin()) == '\n')
-    ret.resize(ret.size() - 1);
-  fclose(fp);
-  return ret;
+  // Strip anything from the first newline char.
+  size_t newline_pos = machine_type.find('\n');
+  if (newline_pos != string::npos)
+    machine_type.erase(newline_pos);
+  return machine_type;
 }
 }  // namespace {}
 
diff --git a/omaha_response_handler_action_unittest.cc b/omaha_response_handler_action_unittest.cc
index 87fa1e8..9da48a6 100644
--- a/omaha_response_handler_action_unittest.cc
+++ b/omaha_response_handler_action_unittest.cc
@@ -107,7 +107,7 @@
     EXPECT_EQ(in.hash, install_plan.download_hash);
     EXPECT_EQ("/dev/sda5", install_plan.install_path);
     string deadline;
-    EXPECT_TRUE(utils::ReadFileToString(
+    EXPECT_TRUE(utils::ReadFile(
         OmahaResponseHandlerAction::kDeadlineFile,
         &deadline));
     EXPECT_EQ("20101020", deadline);
@@ -133,7 +133,7 @@
     EXPECT_EQ(in.hash, install_plan.download_hash);
     EXPECT_EQ("/dev/sda3", install_plan.install_path);
     string deadline;
-    EXPECT_TRUE(utils::ReadFileToString(
+    EXPECT_TRUE(utils::ReadFile(
         OmahaResponseHandlerAction::kDeadlineFile,
         &deadline) && deadline.empty());
   }
@@ -154,7 +154,7 @@
     EXPECT_EQ(in.hash, install_plan.download_hash);
     EXPECT_EQ("/dev/sda5", install_plan.install_path);
     string deadline;
-    EXPECT_TRUE(utils::ReadFileToString(
+    EXPECT_TRUE(utils::ReadFile(
         OmahaResponseHandlerAction::kDeadlineFile,
         &deadline));
     EXPECT_EQ("some-deadline", deadline);
diff --git a/test_utils.cc b/test_utils.cc
index 40d300c..fddd2d1 100644
--- a/test_utils.cc
+++ b/test_utils.cc
@@ -138,31 +138,27 @@
   return ret;
 }
 
-string BindToUnusedLoopDevice(const string &filename) {
-  // get a loop device we can use for the install device
-  string cmd = "losetup --show -f " + filename;
+// Binds provided |filename| to an unused loopback device, whose name is written
+// to the string pointed to by |lo_dev_name_p|. Returns true on success, false
+// otherwise (along with corresponding test failures), in which case the content
+// of |lo_dev_name_p| is unknown.
+bool BindToUnusedLoopDevice(const string& filename, string* lo_dev_name_p) {
+  CHECK(lo_dev_name_p);
 
-  FILE* find_dev_cmd = popen(cmd.c_str(), "r");
-  CHECK(find_dev_cmd);
-
-  string ret;
-  char dev[100] = {0};
-  size_t r;
-  while ((r = fread(dev, 1, sizeof(dev - 1), find_dev_cmd)) > 0) {
-    EXPECT_LT(r, sizeof(dev));
-    ret.insert(ret.end(), dev, dev + r);
+  // Bind to an unused loopback device, sanity check the device name.
+  lo_dev_name_p->clear();
+  if (!(utils::ReadPipe("losetup --show -f " + filename, lo_dev_name_p) &&
+        StartsWithASCII(*lo_dev_name_p, "/dev/loop", true))) {
+    ADD_FAILURE();
+    return false;
   }
-  EXPECT_EQ(r, 0);
-  EXPECT_TRUE(feof(find_dev_cmd));
-  fclose(find_dev_cmd);
 
-  // strip trailing \n on dev
-  if (*ret.rbegin() == '\n')
-    ret.resize(ret.size() - 1);
+  // Strip anything from the first newline char.
+  size_t newline_pos = lo_dev_name_p->find('\n');
+  if (newline_pos != string::npos)
+    lo_dev_name_p->erase(newline_pos);
 
-  // Ensure that the device starts with "/dev/loop"
-  EXPECT_TRUE(StartsWithASCII(ret, "/dev/loop", true));
-  return ret;
+  return true;
 }
 
 bool ExpectVectorsEq(const vector<char>& expected, const vector<char>& actual) {
diff --git a/test_utils.h b/test_utils.h
index 86ee030..6d85157 100644
--- a/test_utils.h
+++ b/test_utils.h
@@ -36,7 +36,8 @@
 // the first partition is marked bootable.
 std::vector<char> GenerateSampleMbr();
 
-std::string BindToUnusedLoopDevice(const std::string &filename);
+bool BindToUnusedLoopDevice(const std::string &filename,
+                            std::string* lo_dev_name_ptr);
 
 // Returns true iff a == b
 bool ExpectVectorsEq(const std::vector<char>& a, const std::vector<char>& b);
@@ -114,13 +115,17 @@
 class ScopedLoopbackDeviceBinder {
  public:
   ScopedLoopbackDeviceBinder(const std::string& file, std::string* dev) {
-    dev_ = BindToUnusedLoopDevice(file);
+    is_bound_ = BindToUnusedLoopDevice(file, &dev_);
+    EXPECT_TRUE(is_bound_);
 
-    if (dev)
+    if (is_bound_ && dev)
       *dev = dev_;
   }
 
   ~ScopedLoopbackDeviceBinder() {
+    if (!is_bound_)
+      return;
+
     for (int retry = 0; retry < 5; retry++) {
       std::vector<std::string> args;
       args.push_back("/sbin/losetup");
@@ -136,10 +141,14 @@
     ADD_FAILURE();
   }
 
-  const std::string &dev() { return dev_; }
+  const std::string &dev() {
+    EXPECT_TRUE(is_bound_);
+    return dev_;
+  }
 
  private:
   std::string dev_;
+  bool is_bound_;
   DISALLOW_COPY_AND_ASSIGN(ScopedLoopbackDeviceBinder);
 };
 
diff --git a/utils.cc b/utils.cc
index 9cb8053..e0d9244 100644
--- a/utils.cc
+++ b/utils.cc
@@ -141,33 +141,70 @@
 
 }
 
-bool ReadFile(const std::string& path, std::vector<char>* out) {
-  CHECK(out);
+// Append |nbytes| of content from |buf| to the vector pointed to by either
+// |vec_p| or |str_p|.
+static void AppendBytes(const char* buf, size_t nbytes,
+                        std::vector<char>* vec_p) {
+  CHECK(buf);
+  CHECK(vec_p);
+  vec_p->insert(vec_p->end(), buf, buf + nbytes);
+}
+static void AppendBytes(const char* buf, size_t nbytes,
+                        std::string* str_p) {
+  CHECK(buf);
+  CHECK(str_p);
+  str_p->append(buf, nbytes);
+}
+
+// Reads from an open file |fp|, appending the read content to the container
+// pointer to by |out_p|.  Returns true upon successful reading all of the
+// file's content, false otherwise.
+template <class T>
+static bool Read(FILE* fp, T* out_p) {
+  CHECK(fp);
+  char buf[1024];
+  while (size_t nbytes = fread(buf, 1, sizeof(buf), fp))
+    AppendBytes(buf, nbytes, out_p);
+  return feof(fp) && !ferror(fp);
+}
+
+// Opens a file |path| for reading, then uses |append_func| to append its
+// content to a container |out_p|.
+template <class T>
+static bool ReadFileAndAppend(const std::string& path, T* out_p) {
   FILE* fp = fopen(path.c_str(), "r");
   if (!fp)
     return false;
-  const size_t kChunkSize = 1024;
-  size_t read_size;
-  do {
-    char buf[kChunkSize];
-    read_size = fread(buf, 1, kChunkSize, fp);
-    if (read_size == 0)
-      break;
-    out->insert(out->end(), buf, buf + read_size);
-  } while (read_size == kChunkSize);
-  bool success = !ferror(fp);
-  TEST_AND_RETURN_FALSE_ERRNO(fclose(fp) == 0);
-  return success;
+  bool success = Read(fp, out_p);
+  return (success && !fclose(fp));
 }
 
-bool ReadFileToString(const std::string& path, std::string* out) {
-  vector<char> data;
-  bool success = ReadFile(path, &data);
-  if (!success) {
+// Invokes a pipe |cmd|, then uses |append_func| to append its stdout to a
+// container |out_p|.
+template <class T>
+static bool ReadPipeAndAppend(const std::string& cmd, T* out_p) {
+  FILE* fp = popen(cmd.c_str(), "r");
+  if (!fp)
     return false;
-  }
-  (*out) = string(&data[0], data.size());
-  return true;
+  bool success = Read(fp, out_p);
+  return (success && pclose(fp) >= 0);
+}
+
+
+bool ReadFile(const std::string& path, std::vector<char>* out_p) {
+  return ReadFileAndAppend(path, out_p);
+}
+
+bool ReadFile(const std::string& path, std::string* out_p) {
+  return ReadFileAndAppend(path, out_p);
+}
+
+bool ReadPipe(const std::string& cmd, std::vector<char>* out_p) {
+  return ReadPipeAndAppend(cmd, out_p);
+}
+
+bool ReadPipe(const std::string& cmd, std::string* out_p) {
+  return ReadPipeAndAppend(cmd, out_p);
 }
 
 off_t FileSize(const string& path) {
diff --git a/utils.h b/utils.h
index 67e8062..1b3095b 100644
--- a/utils.h
+++ b/utils.h
@@ -48,9 +48,18 @@
 bool PReadAll(int fd, void* buf, size_t count, off_t offset,
               ssize_t* out_bytes_read);
 
-// Returns the entire contents of the file at path. Returns true on success.
-bool ReadFile(const std::string& path, std::vector<char>* out);
-bool ReadFileToString(const std::string& path, std::string* out);
+// Opens |path| for reading and appends its entire content to the container
+// pointed to by |out_p|. Returns true upon successfully reading all of the
+// file's content, false otherwise, in which case the state of the output
+// container is unknown.
+bool ReadFile(const std::string& path, std::vector<char>* out_p);
+bool ReadFile(const std::string& path, std::string* out_p);
+
+// Invokes |cmd| in a pipe and appends its stdout to the container pointed to by
+// |out_p|. Returns true upon successfully reading all of the output, false
+// otherwise, in which case the state of the output container is unknown.
+bool ReadPipe(const std::string& cmd, std::vector<char>* out_p);
+bool ReadPipe(const std::string& cmd, std::string* out_p);
 
 // Returns the size of the file at path. If the file doesn't exist or some
 // error occurrs, -1 is returned.