c/c++ linux programming by examples my programming tips and techniques

We can actually do this to print text on screen,

fprintf(stdout,"Hello %s\n","World");

But why?

Try to imagine that you are doing a debug log file function, which to print “debug string” to a file with specified FILE such as this

So when you want to write the debug string to file, pass the “file output stream”, print on screen? pass “stdout”.

FILE is a stream object, when you create a stream pointer, you can point to stdout. stdout is a standard output defined when you initiate main(). You can do something fun, look at another example bellow

The code above redirect the standard output to a file “out-snap” and I uses fp to preserved the stdout address. Later I do fclose(stdout), I was actually closing the file stream and point back the stdout to standard output.