Can anybody tell me what is the use of c_str() function in C/C++?. In which case it is necessary to use it?.
4 Answers
It is a C++ thing, not a C one.
A common use of c_str (from std::string) is precisely to convert a C++ std::string to a const char* C string, which is required by many many low level C functions (e.g. Posix system calls like stat, etc).
Comments
Generates a null-terminated sequence of characters (c-string) with the same content as the string object and returns it as a pointer to an array of characters.
There is a good example of its use here: http://www.cplusplus.com/reference/string/string/c_str/