Add remove_file and rename_file to QUtil

ChangeLog

@@ -1,3 +1,7 @@
+2019-08-31  Jay Berkenbilt  <ejb@ql.org>
+
+	* Add methods rename_file and remove_file to QUtil.
+
 2019-08-24  Jay Berkenbilt  <ejb@ql.org>
 
 	* Add QPDF::userPasswordMatched() and QPDF::ownerPasswordMatched()

include/qpdf/QUtil.hh

@@ -110,6 +110,13 @@ namespace QUtil
     QPDF_DLL
     bool same_file(char const* name1, char const* name2);
 
+    QPDF_DLL
+    void remove_file(char const* path);
+
+    // rename_file will overwrite newname if it exists
+    QPDF_DLL
+    void rename_file(char const* oldname, char const* newname);
+
     QPDF_DLL
     char* copy_string(std::string const&);
 

libqpdf/QUtil.cc

@@ -394,15 +394,14 @@ QUtil::os_wrapper(std::string const& description, int status)
     return status;
 }
 
-FILE*
-QUtil::safe_fopen(char const* filename, char const* mode)
-{
-    FILE* f = 0;
 #ifdef _WIN32
+static PointerHolder<wchar_t>
+win_convert_filename(char const* filename)
+{
     // Convert the utf-8 encoded filename argument to wchar_t*. First,
     // convert to utf16, then to wchar_t*. Note that u16 will start
     // with the UTF16 marker, which we skip.
-    std::string u16 = utf8_to_utf16(filename);
+    std::string u16 = QUtil::utf8_to_utf16(filename);
     size_t len = u16.length();
     size_t wlen = (len / 2) - 1;
     PointerHolder<wchar_t> wfilenamep(true, new wchar_t[wlen + 1]);
@@ -415,6 +414,17 @@ QUtil::safe_fopen(char const* filename, char const* mode)
                 (static_cast<unsigned char>(u16.at(i)) << 8) +
                 static_cast<unsigned char>(u16.at(i+1)));
     }
+    return wfilenamep;
+}
+#endif
+
+FILE*
+QUtil::safe_fopen(char const* filename, char const* mode)
+{
+    FILE* f = 0;
+#ifdef _WIN32
+    PointerHolder<wchar_t> wfilenamep = win_convert_filename(filename);
+    wchar_t* wfilename = wfilenamep.getPointer();
     PointerHolder<wchar_t> wmodep(true, new wchar_t[strlen(mode) + 1]);
     wchar_t* wmode = wmodep.getPointer();
     wmode[strlen(mode)] = 0;
@@ -537,6 +547,40 @@ QUtil::same_file(char const* name1, char const* name2)
     return false;
 }
 
+
+void
+QUtil::remove_file(char const* path)
+{
+#ifdef _WIN32
+    PointerHolder<wchar_t> wpath = win_convert_filename(path);
+    os_wrapper(std::string("remove ") + path, _wunlink(wpath.getPointer()));
+#else
+    os_wrapper(std::string("remove ") + path, unlink(path));
+#endif
+}
+
+void
+QUtil::rename_file(char const* oldname, char const* newname)
+{
+#ifdef _WIN32
+    try
+    {
+        remove_file(newname);
+    }
+    catch (QPDFSystemError&)
+    {
+        // ignore
+    }
+    PointerHolder<wchar_t> wold = win_convert_filename(oldname);
+    PointerHolder<wchar_t> wnew = win_convert_filename(newname);
+    os_wrapper(std::string("rename ") + oldname + " " + newname,
+               _wrename(wold.getPointer(), wnew.getPointer()));
+#else
+    os_wrapper(std::string("rename ") + oldname + " " + newname,
+               rename(oldname, newname));
+#endif
+}
+
 char*
 QUtil::copy_string(std::string const& str)
 {

libtests/qtest/qutil/qutil.out

@@ -99,3 +99,9 @@ read 24652 bytes
 ---- hex encode/decode
 begin hex encode/decode
 end hex encode/decode
+---- rename/delete
+create file
+rename file
+create file
+rename over existing
+delete file

libtests/qutil.cc

@@ -457,6 +457,57 @@ void hex_encode_decode_test()
     std::cout << "end hex encode/decode\n";
 }
 
+static void assert_no_file(char const* filename)
+{
+    try
+    {
+        fclose(QUtil::safe_fopen(filename, "r"));
+        assert(false);
+    }
+    catch (QPDFSystemError&)
+    {
+    }
+}
+
+void rename_delete_test()
+{
+    PointerHolder<char> buf;
+    size_t size = 0;
+
+    try
+    {
+        QUtil::remove_file("old\xcf\x80");
+    }
+    catch (QPDFSystemError&)
+    {
+    }
+    assert_no_file("old\xcf\x80");
+    std::cout << "create file" << std::endl;;
+    FILE* f1 = QUtil::safe_fopen("old\xcf\x80", "w");
+    fprintf(f1, "one");
+    fclose(f1);
+    QUtil::read_file_into_memory("old\xcf\x80", buf, size);
+    assert(memcmp(buf.getPointer(), "one", 3) == 0);
+    std::cout << "rename file" << std::endl;;
+    QUtil::rename_file("old\xcf\x80", "old\xcf\x80.~tmp");
+    QUtil::read_file_into_memory("old\xcf\x80.~tmp", buf, size);
+    assert(memcmp(buf.getPointer(), "one", 3) == 0);
+    assert_no_file("old\xcf\x80");
+    std::cout << "create file" << std::endl;;
+    f1 = QUtil::safe_fopen("old\xcf\x80", "w");
+    fprintf(f1, "two");
+    fclose(f1);
+    std::cout << "rename over existing" << std::endl;;
+    QUtil::rename_file("old\xcf\x80", "old\xcf\x80.~tmp");
+    QUtil::read_file_into_memory("old\xcf\x80.~tmp", buf, size);
+    assert(memcmp(buf.getPointer(), "two", 3) == 0);
+    assert_no_file("old\xcf\x80");
+    std::cout << "delete file" << std::endl;;
+    QUtil::remove_file("old\xcf\x80.~tmp");
+    assert_no_file("old\xcf\x80");
+    assert_no_file("old\xcf\x80.~tmp");
+}
+
 int main(int argc, char* argv[])
 {
     try
@@ -485,6 +536,8 @@ int main(int argc, char* argv[])
 	read_from_file_test();
 	std::cout << "---- hex encode/decode" << std::endl;
 	hex_encode_decode_test();
+	std::cout << "---- rename/delete" << std::endl;
+	rename_delete_test();
     }
     catch (std::exception& e)
     {