fix(util): 添加ReadFistLineFromTextFile()，并修复读取文件行存在多余的\r的问题

Author: hevake

modules/util/fs.cpp

@@ -73,9 +73,33 @@ bool ReadEachLineFromTextFile(const std::string &filename, const std::function<v
     try {
         ifstream f(filename);
         if (f) {
-            std::string line;
-            while (std::getline(f, line))
-                line_handle_func(line);
+            std::string text;
+            while (std::getline(f, text)) {
+                while (!text.empty() && (text.back() == '\r' || text.back() == '\n'))
+                    text.pop_back();
+                line_handle_func(text);
+            }
+            return true;
+        } else {
+            LogWarn("open failed, %s", filename.c_str());
+        }
+    } catch (const exception &e) {
+        LogWarn("catch exception: %s", e.what());
+    }
+    return false;
+}
+
+bool ReadAllLinesFromTextFile(const std::string &filename, std::vector<std::string> &text_vec)
+{
+    try {
+        ifstream f(filename);
+        if (f) {
+            std::string text;
+            while (std::getline(f, text)) {
+                while (!text.empty() && (text.back() == '\r' || text.back() == '\n'))
+                    text.pop_back();
+                text_vec.emplace_back(std::move(text));
+            }
             return true;
         } else {
             LogWarn("open failed, %s", filename.c_str());
@@ -86,14 +110,14 @@ bool ReadEachLineFromTextFile(const std::string &filename, const std::function<v
     return false;
 }
 
-bool ReadAllLinesFromTextFile(const std::string &filename, std::vector<std::string> &lines)
+bool ReadFirstLineFromTextFile(const std::string &filename, std::string &text)
 {
     try {
         ifstream f(filename);
         if (f) {
-            std::string line;
-            while (std::getline(f, line))
-                lines.emplace_back(std::move(line));
+            std::getline(f, text);
+            while (!text.empty() && (text.back() == '\r' || text.back() == '\n'))
+                text.pop_back();
             return true;
         } else {
             LogWarn("open failed, %s", filename.c_str());

modules/util/fs.h

@@ -74,6 +74,17 @@ bool ReadEachLineFromTextFile(const std::string &filename, const std::function<v
  */
 bool ReadAllLinesFromTextFile(const std::string &filename, std::vector<std::string> &lines);
 
+/**
+ * 从文件中读取第一行文本
+ *
+ * \param filename          文件名
+ * \param text              读出的行内容
+ *
+ * \return true     文件打开成功
+ * \return false    文件打开失败
+ */
+bool ReadFirstLineFromTextFile(const std::string &filename, std::string &text);
+
 /**
  * 将字串写入到文件
  *

modules/util/fs_test.cpp

@@ -71,7 +71,7 @@ TEST(fs, TextFileReadAppend_Ok) {
 
 TEST(fs, TextFileReadEachLine) {
     ::unlink(test_filename);  //! 先删一次
-    const std::string text_tobe_write = "first line\nsecond line\nthird line";
+    const std::string text_tobe_write = "first line\r\nsecond line\nthird line";
     EXPECT_TRUE(WriteStringToTextFile(test_filename, text_tobe_write)); //! 写入数据
     std::vector<std::string> str_vec;
     bool ret = ReadEachLineFromTextFile(test_filename,
@@ -84,6 +84,19 @@ TEST(fs, TextFileReadEachLine) {
     EXPECT_EQ(str_vec[2], "third line");
 }
 
+TEST(fs, TextFileReadFirstLine) {
+    ::unlink(test_filename);  //! 先删一次
+    EXPECT_TRUE(WriteStringToTextFile(test_filename, "first line\r\n")); //! 写入数据
+    std::string text;
+    EXPECT_TRUE(ReadFirstLineFromTextFile(test_filename, text));
+    ASSERT_EQ(text, "first line");
+
+    ::unlink(test_filename);  //! 先删一次
+    EXPECT_TRUE(WriteStringToTextFile(test_filename, "one line")); //! 写入数据
+    EXPECT_TRUE(ReadFirstLineFromTextFile(test_filename, text));
+    ASSERT_EQ(text, "one line");
+}
+
 TEST(fs, FileFail) {
     EXPECT_FALSE(WriteStringToTextFile(test_filename_cannot_access, "Hello"));
     std::string text_tobe_read;