Question

I’m trying to compile a simple “hello world”

file_name

#include <stdio.h>
void main () {
    printf ("Hello World\n");
}

then I try: gcc file_name and I get “File not recognized. File format not recognized”

I however am 100% sure I did the exact same thing a few weeks back (just to see if it works, as now) and it worked, so I just don’t get it.

gcc -ver // returns 4.6.1 if this helpes

Also how is gcc -o supposed to work ? The manual (man gcc) is just gibberish at times (for me)

Answer 1

gcc tries to guess the language used (e.g. C or C++) based on the extension of the file, so you need to ensure you have the proper file extension (usually .cpp for C++ and .c for C dource files). Alternatively, read the manual if there is a command line option to explicitly state the format (regardless of the extension).

As for the “-o” command line parameter: the name specified after that option is the name of the object file created from the compiled source file. The object files are then linked together to form an executable