Rules of automatic flushing stdout buffer is implementation-defined (ID). It is ID when the stream is unbuffered, fully buffered, or line buffered. When a stream is unbuffered, characters are intended to appear from the source or at the destination as soon as possible. Otherwise characters may be accumulated and transmitted to or from the host … Read more
Why use freopen()? The C89 specification has the answer in one of the endnotes for the section on <stdio.h>: 116. The primary use of the freopen function is to change the file associated with a standard text stream (stderr, stdin, or stdout), as those identifiers need not be modifiable lvalues to which the value returned … Read more
I’m surprised that everyone in this question claims that std::cout is way better than printf, even if the question just asked for differences. Now, there is a difference – std::cout is C++, and printf is C (however, you can use it in C++, just like almost anything else from C). Now, I’ll be honest here; … Read more
The Beginner’s C Input Primer Text mode vs. Binary mode Check fopen() for failure Pitfalls Check any functions you call for success EOF, or “why does the last line print twice” Do not use gets(), ever Do not use fflush() on stdin or any other stream open for reading, ever Do not use *scanf() for … Read more