From the glibc sprintf() documentation: The behavior of this function is undefined if copying takes place between objects that overlap—for example, if s is also given as an argument to be printed under control of the ‘%s’ conversion. It may be safe in a particular implementation; but you could not count on it being portable. … Read more
http://en.wikipedia.org/wiki/Ascii#ASCII_control_code_chart Binary Oct Dec Hex Abbr Unicode Control char C Escape code Name 0000000 000 0 00 NUL ␀ ^@ \0 Null character There’s no difference, but the more idiomatic one is ‘\0’. Putting it down as char c = 0; could mean that you intend to use it as a number (e.g. a counter). … Read more
Uhm.. way too complicated. Go for this one: int strCmp(const char* s1, const char* s2) { while(*s1 && (*s1 == *s2)) { s1++; s2++; } return *(const unsigned char*)s1 – *(const unsigned char*)s2; } It returns <0, 0 or >0 as expected You can’t do it without pointers. In C, indexing an array is using … Read more
strdup allocates a copy of the string on the heap, which you have to free manually later (with free() I think). If you have the option, it would be much better to return std::string. The static storage of out doesn’t help, because .str() returns a temporary std::string, which is destroyed when the function exits.
Got My answer. Thanks for your support @Elliot Tereschuk. I have gone through some references like How to: Extend the Marshaling Library Overview of Marshaling in C++ For CString.Format() and include header files #include <msclr/marshal_windows.h> #include <msclr/marshal.h> using Library using namespace msclr::interop; And finally My source code is. String^ csPass = gcnew String(strPassword.GetBuffer()); array<Byte>^ Value … Read more
Variable char* matches[1]; is declared on the stack, and it will be automatically released when the current block goes out of scope. This means when you return matches, memory reserved for matches will be freed, and your pointer will point to something that you don’t want to. You can solve this in many ways, and … Read more
Is it possible to print out only the last 5 bytes of this string? Yes, just pass a pointer to the fifth-to-the-last character. You can determine this by string + strlen(string) – 5. What about the first 5 bytes only? Use a precision specifier: %.5s #include <stdio.h> #include <string.h> char* string = “Hello, how are … Read more
Can someone explains why the compiler shows like that…? Yes, because, the gets() function is dangerous, as it suffers from buffer overflow issue. Anyone should refrain from using that. Also, regarding the warning with -Wdeprecated-declarations, gets() is no longer a part of C standard [C11 onwards]. So, C libraries compilers are not bound to support … Read more
What are null-terminating strings? In C, a “null-terminated string” is a tautology. A string is, by definition, a contiguous null-terminated sequence of characters (an array, or a part of an array). Other languages may address strings differently. I am only discussing C strings. How are they different from a non-null-terminated strings? There are no non-null-terminated … Read more
Two reasons I can think of: It’s not strictly ANSI C, but rather POSIX. Consequently, some compilers (e.g. MSVC) discourage use (MSVC prefers _strdup), and technically the C standard could define its own strdup with different semantics since str is a reserved prefix. So, there are some potential portability concerns with its use. It hides … Read more