How to print buffer to stdout within c++?

Question

How can I print a buffer in my stdout for debugging purposes? I'm currently a beginner working with OpenGL within XCode (for an iOS app) and have the below lines of code.

GLubyte *buffer = (GLubyte *)malloc(myDataLength);
glReadPixels(0, 0, 320, 480, GL_RGBA, GL_UNSIGNED_BYTE, buffer);

I'd simply like to print to the console the buffer although when trying: fprintf(stderr, buffer); I receive an error "No matching function for call to 'fprintf'.

Iterate over the individual content in `GLubyte`, whatever that is, and print each value, individually. — Sam Varshavchik, Nov 26 '16 at 16:24
Your question is improving, but please show all of your relevant code so we can see what you've done. — byxor, Nov 26 '16 at 16:31
Do you want to output all the contents of buffer to console? — Asesh, Nov 26 '16 at 17:10

score -2 · Answer 1 · edited May 23 '17 at 11:52

-2

"fprintf" needs at least 3 argumens (output file, string format, argument) while you provide only 2. C++ compiler tells you that cannot find a matching signature of fprintf with 2 arguments. Besides, there is one more issue to be solved. The buffer probably contains non printable characters so the correct call of fprintf may will not give you the expected result. I would suggest to use a custom buffer printing method maybe something like this Printing char buffer in hex array

edited May 23 '17 at 11:52

Community

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answered Nov 26 '16 at 16:45

Thettalos

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fprintf requires only 2 arguments. – stark Nov 26 '16 at 17:01

How to print buffer to stdout within c++?

1 Answers1