Question

I am required to explain what the program located in the following links does:

main.c

csapp.c

csapp.h

I compile the following code in linux as:

……………………………………………………

(note all three files have to be in the same working directory for compilation to work. )

that command is: gcc main.c csapp.c

when I execute that command I get the executable: a.out and I get no compilation errors!

That executable file can be downloaded from here (I don’t think you need that file plus I will not execute that file if I where you).

Anyways I think that if I could debug the program I will be able to understand better what is going on. As a result I have created a C++ console empty console project in visual studio. I will like to include the same files in there and be able to compile it. I have never used c++ before and I don’t really understand where to place header files. This is what I have done hoping to be able to compile the program:

The program will not compile if I place the files like that.

I have also tried placing all the files in the same directory just like on the linux virtual machine:

that does not compile either.

How will I be able to compile that program with visual studio?

Answer 1

If you look at csapp.h you’ll notice it tries to include these headers:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <setjmp.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <errno.h>
#include <math.h>
#include <pthread.h>
#include <semaphore.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>

Some of these are std C headers, but others are specific to POSIX/Linux/UNIX style operating systems (pthread.h for example). You won’t be able to use these libraries on Windows or in Visual Studio unless you’re doing something unusual like compiling against Cygwin libraries.

If you want to get an understanding of what the program is doing, there’s a number of things you could do. First off, just read through the code and look up the functions it calls in the man pages which document those functions (If you have gcc, I guess you also have man?) second, yes you could print to console to figure stuff out. You could also use a debugger like gdb to step through the program, it’s not as intuitive as VS debugger but it works…