C vs C++ .. watta hell's goin'on??

minike · 04-24-2005, 10:50 PM

Hello.. just today I made my first program in C (with the help of the people in here) , but what I compile in C, when I try to compile in C++ (with c++ syntax and .cc suffix) returns me a hugh amount of errors ... and I don't know why.. I have searched using google, and I guess I've got all of the requied libraries..really don't know what to think..
Here I paste the error msg, if somebody can figure what's wrong, please let me know, coz I need to compile in c++ . Thanks in advance.

////// Error msg:
gcc: pr: No such file or directory // <- yes it's there!!
In file included from /usr/include/c++/3.3.4/backward/iostream.h:31,
from pr.cpp:2:
/usr/include/c++/3.3.4/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X> header for the <X.h> header for C++ includes, or <sstream> instead of the deprecated header <strstream.h>. To disable this warning use -Wno-deprecated.
In file included from /usr/include/bits/posix1_lim.h:126,
from /usr/include/limits.h:144,
from /usr/lib/gcc-lib/i486-slackware-linux/3.3.4/include/limits.h:122,
from /usr/lib/gcc-lib/i486-slackware-linux/3.3.4/include/syslimits.h:7,
from /usr/lib/gcc-lib/i486-slackware-linux/3.3.4/include/limits.h:11,
from /usr/include/c++/3.3.4/climits:49,
from /usr/include/c++/3.3.4/bits/stl_algobase.h:66,
from /usr/include/c++/3.3.4/memory:54,
from /usr/include/c++/3.3.4/string:48,
from /usr/include/c++/3.3.4/bits/locale_classes.h:47,
from /usr/include/c++/3.3.4/bits/ios_base.h:47,
from /usr/include/c++/3.3.4/ios:49,
from /usr/include/c++/3.3.4/ostream:45,
from /usr/include/c++/3.3.4/iostream:45,
from /usr/include/c++/3.3.4/backward/iostream.h:32,
from pr.cpp:2:
/usr/include/bits/local_lim.h:36:26: linux/limits.h: No such file or directory
In file included from /usr/include/errno.h:36,
from /usr/include/c++/3.3.4/cerrno:48,
from /usr/include/c++/3.3.4/bits/locale_facets.tcc:38,
from /usr/include/c++/3.3.4/locale:47,
from /usr/include/c++/3.3.4/bits/ostream.tcc:37,
from /usr/include/c++/3.3.4/ostream:535,
from /usr/include/c++/3.3.4/iostream:45,
from /usr/include/c++/3.3.4/backward/iostream.h:32,
from pr.cpp:2:
/usr/include/bits/errno.h:25:26: linux/errno.h: No such file or directory

rununix · 04-24-2005, 10:57 PM

1. it helps to see the code, because we got no clue what your #include's look like
2. You are using deprecated header files in your includes like #include <iostream.h>
What you need to do is use #include <iostream>
3. The above is a general advice. Not all <xxx.h> headers are deprecated though so be careful.

reddazz · 04-24-2005, 11:01 PM

Paste the code you are trying to compile. Lets say you write a program that prints "Hello, World!" to the screen, in C, the syntax is

Code:

#include <stdio.h>
int main (void)
{
      printf ("Hello, World!\n");
      
      return 0;
}

To compile it you would do,

Code:

gcc -o hello hello.c

The same program in c++ would be

Code:

#include <iostream>
using namespace std;
int main (void)
{
      cout << "Hello, World!\n";
      
      return 0;
}

To compile it you would do,

Code:

g++ -o hello hello.cpp

minike · 04-24-2005, 11:04 PM

ok...here's the code.. it's just a hello world one..
#include <stdlib.h>
#include<iostream.h>
int main (void) {

cout<<"hola topu!!"<<endl;
return 0;
}
have in mind I've proved without the .h suffix in the includes, but the result is the same

minike · 04-24-2005, 11:09 PM

hi, reddazz...
plz tell me what's the 2nd line in your cpp example! this:
using namespace std;
it's the very first time I see such code!

rununix · 04-24-2005, 11:37 PM

#include <stdlib.h>
#include<iostream>
using namespace std;
int main (void) {

cout<<"hola topu!!"<<endl;
return 0;
}

using namespace std; tells where to look for cout command.
if you don't have that directive you have to do this: std::cout<<....

reddazz · 04-24-2005, 11:54 PM

Quote:

Originally posted by minike
ok...here's the code.. it's just a hello world one..
#include <stdlib.h>
#include<iostream.h>
int main (void) {

cout<<"hola topu!!"<<endl;
return 0;
}
have in mind I've proved without the .h suffix in the includes, but the result is the same

Your code could also be written as below,

Code:

#include <cstdlib>
#include <iostream>
using namespace std;
int main (void)
{
    cout << "hola topu!!";

    return 0;
}

Hivemind · 04-25-2005, 02:59 AM

You should remove the <cstdlib> include from the C++-version reddazz posted, it's not used in the program. And you should also consider flushing the output buffer or you might not see the output.

Code:

cout << "hola topu!!" << endl;

takes care of that.

reddazz · 04-25-2005, 03:13 AM

I put that in so it was the same as his code, but its not necessary for a simple program.

minike · 04-25-2005, 09:57 AM

ok, pals..
I just fixed the problem: I've had not the kernel-headers library..
that's why I always recommend have in mind my minimal distro..
now it comes all the "deprecated" headers stuff, but they're just warnings -not fatal errors.
tons of thanks to all of you, and to gbonvehi as well.