Add ftell

CMakeLists.txt

@@ -26,6 +26,8 @@ if (WIN32)
 else()
     check_symbol_exists(fseeko "stdio.h" HAVE_FSEEKO)
     check_symbol_exists(fseeko64 "stdio.h" HAVE_FSEEKO64)
+    check_symbol_exists(ftello "stdio.h" HAVE_FTELLO)
+    check_symbol_exists(ftello64 "stdio.h" HAVE_FTELLO64)
 endif()
 check_symbol_exists(strerror_r "string.h" HAVE_STRERROR_R)
 if (HAVE_STRERROR_R)

fileop.cpp

@@ -440,3 +440,17 @@ int fileop::fseek(FILE* f, int64_t offset, int origin) {
 bool fileop::mkdir_for_file(std::string path, int mode) {
     return mkdirs(dirname(path), mode, true);
 }
+
+int64_t fileop::ftell(FILE* f) {
+#if _WIN32
+    return ::_ftelli64(f);
+#else
+#if HAVE_FTELLO64
+    return ::ftello64(f);
+#elif HAVE_FTELLO
+    return ::ftello(f);
+#else
+    return ::ftell(f);
+#endif
+#endif
+}

fileop.h

@@ -148,5 +148,11 @@ namespace fileop {
      * @return true if file's directory is exists now.
     */
     bool mkdir_for_file(std::string path, int mode);
+    /**
+     * @brief Gets the current position of a file pointer.
+     * @param f Target FILE structure.
+     * @return The current position
+    */
+    int64_t ftell(FILE* f);
 }
 #endif

utils_config.h.in

@@ -10,3 +10,5 @@
 #cmakedefine HAVE_SSCANF_S @HAVE_SSCANF_S@
 #cmakedefine HAVE_FSEEKO @HAVE_FSEEKO@
 #cmakedefine HAVE_FSEEKO64 @HAVE_FSEEKO64@
+#cmakedefine HAVE_FTELLO @HAVE_FTELLO@
+#cmakedefine HAVE_FTELLO64 @HAVE_FTELLO64@