diff --git a/src/lib/dstring.cpp b/src/lib/dstring.cpp
index 21d5441..1349d9d 100644
--- a/src/lib/dstring.cpp
+++ b/src/lib/dstring.cpp
@@ -49,28 +49,6 @@ std::vector<std::string> DString::splitStr(const std::string &str, char c)
     return splitChars(str.c_str(), c);
 }
 
-std::vector<std::string> DString::splitVectorChars(const std::vector<char> &content, size_t length, char c)
-{
-    std::vector<std::string> ret;
-    size_t pos = 0;
-    bool hasChar = true;
-    for (size_t i = 0; i < length; i++) {
-        if (content[i] == c && i > pos && hasChar) {
-            std::string str;
-            for (size_t j = pos; j <= i; j++) {
-                str += std::string(1, content[j]);
-            }
-            ret.push_back(str);
-            pos = i + 1;
-            hasChar = false;
-        } else {
-            hasChar = true;
-        }
-    }
-
-    return ret;
-}
-
 bool DString::startWith(const char *chars, const char *prefix)
 {
     if (!chars || !prefix) {
diff --git a/src/lib/dstring.h b/src/lib/dstring.h
index ea8072f..63a4b03 100644
--- a/src/lib/dstring.h
+++ b/src/lib/dstring.h
@@ -24,7 +24,6 @@ public:
     // 字符串拆分
     static std::vector<std::string> splitChars(const char *cs, char c);
     static std::vector<std::string> splitStr(const std::string &str, char c);
-    static std::vector<std::string> splitVectorChars(const std::vector<char> &content, size_t length, char c);
     // 字符串前缀判断
     static bool startWith(const char *chars, const char *prefix);
     static bool startWith(const std::string &str, const std::string &prefix);
diff --git a/src/lib/process.cpp b/src/lib/process.cpp
index b922fdb..a01e9bf 100644
--- a/src/lib/process.cpp
+++ b/src/lib/process.cpp
@@ -8,6 +8,7 @@
 #include "dfile.h"
 
 #include <algorithm>
+#include <fstream>
 #include <dirent.h>
 #include <unistd.h>
 
@@ -154,18 +155,19 @@ std::string Process::getFile(const std::string &name)
     return "/proc/" + std::to_string(m_pid) + "/" + name;
 }
 
-// /proc is not real file system
+// This funciton only can used to read `environ` and `cmdline`
 std::vector<std::string> Process::readFile(std::string fileName)
 {
     std::vector<std::string> ret;
-    std::FILE *fp = std::fopen(fileName.c_str(), "r");
-    if (!fp)
-        return ret;
+    std::ifstream fs(fileName);
+    if (!fs.is_open()) {
+            return ret;
+    }
 
-    std::vector<char> content(FILECONTENLEN);
-    std::size_t len = std::fread(&content[0], 1, FILECONTENLEN, fp);
-    std::fclose(fp);
+    std::string tmp;
+    while (std::getline(fs, tmp, '\0')) {
+        ret.push_back(tmp);
+    }
 
-    ret = DString::splitVectorChars(content, len, '\0');
     return ret;
 }