Hi,

I am using Ubuntu 6.06 LTS .


Linux version 2.6.15-25-386 (buildd@terranova) (gcc version 4.0.3 (Ubuntu 4.0.3-1ubuntu5))


here is my hello world program

#include <stdio.h>

int main()
{
printf("Hello world");
return 0;
}

when i compile the above program as a c program it works

but when i try to compile the above program as a .cpp program it gives an error

junaid@Dev-jsahibzada:~$ gcc -o client client.cpp
/tmp/ccEBL7jl.o.eh_frame+0x11): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status

can any one tell me what the problem is?

Fist of all that's a C program that is just called cpp :}


Secondly you seem to be missing some library.
Try renaming it to .c instead of .cpp, and compiling it
again with its new name.


Cheers,
Tink

hi TInk,

Thanks for the reply.

actually all c programs are working. only cpp ones are giving me that error

for example the following program

#include <stdio.h>
#include <iostream.h>

int main()
{
cout<<"Hello world\n";
return 0;
}


is giving me the error


junaid@Dev-jsahibzada:~$ gcc -o client client.cpp
In file included from /usr/lib/gcc/i486-linux-gnu/4.0.3/../../../../include/c++/4.0.3/backward/iostream.h:31,
from client.cpp:2:
/usr/lib/gcc/i486-linux-gnu/4.0.3/../../../../include/c++/4.0.3/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 <iostream> instead of the deprecated header <iostream.h>. To disable this warning use -Wno-deprecated.
/tmp/cco9I2s4.o: In function `main':client.cpp.text+0x27): undefined reference to `std::cout'
:client.cpp.text+0x2c): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std:perator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
/tmp/cco9I2s4.o: In function `__tcf_0':client.cpp.text+0x46): undefined reference to `std::ios_base::Init::~Init()'
/tmp/cco9I2s4.o: In function `__static_initialization_and_destruction_0(int, int)':client.cpp.text+0x6f): undefined reference to `std::ios_base::Init::Init()'
/tmp/cco9I2s4.o.eh_frame+0x11): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status

for C++ programs they may use different headers, and youll need to leave out the '.h'.

to compile C++ programs you use g++ not gcc.

This isn't quite true. Calling headers as file.h is deprecated. For c++, you want to include <iostream> and <cstdlib>.

i wasnt saying specifically for the two mentioned.. i was just saying in general, there MAY be different versions of specific ones as a note to the thread starter in the future.

bahadur -

Tinkster's right: GCC is treating your "C" program as though it were C++ (which is apparently what you want), and the linker isn't finding the right C++ runtime binaries.

SOLUTION:
Use "g++" instead of "gcc"
... OR ...
Add "-lstdc++" to the end of your command

EXAMPLE:
BETTER:

ok thanks for the help.

i used g++ instead of gcc and it worked but it still gives me the deprecated warning.

some how i have old libraries on my system.

my code looks like this now



and here is what i get when i compile the program

junaid@Dev-jsahibzada:~$ g++ -o client client.cpp
In file included from /usr/lib/gcc/i486-linux-gnu/4.0.3/../../../../include/c++/4.0.3/backward/iostream.h:31,
from client.cpp:2:
/usr/lib/gcc/i486-linux-gnu/4.0.3/../../../../include/c++/4.0.3/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 <iostream> instead of the deprecated header <iostream.h>. To disable this warning use -Wno-deprecated.

when i use -Wno-deprecated then it works fine.

last of all if i remove the .h from the iostream.h the program simply cant find any include files.

you mean it doesnt show you any warnings

can you show us the command you run and the output with the removed .h's, and the code i guess.

To not use -Wno-deprecated you need to change your code. c++ in recent years add some new features. You can google for more info but here is the basic change.

ok folks here is what the problem was.

long time ago i had installed a wrong set of headers

so now i again resintalled the latest headers

i have the following headers on my system now

junaid@Dev-jsahibzada:~$ sudo find /usr -name '*linux-headers*' -print
/usr/share/doc/linux-headers-2.6.15-25-386
/usr/share/doc/linux-headers-2.6.15-25
/usr/share/doc/linux-headers-2.6.15-26
/usr/share/doc/linux-headers-2.6.15-26-686
/usr/src/linux-headers-2.6.15-25-386
/usr/src/linux-headers-2.6.15-25
/usr/src/linux-headers-2.6.15-25/linux-headers.revision
/usr/src/linux-headers-2.6.15-26-686
/usr/src/linux-headers-2.6.15-26
/usr/src/linux-headers-2.6.15-26/linux-headers.revision


i just installed the 686 ones.

i also added the line using name space std to the code.

and now its not giving me the warning.

i think the problem is fixed.

one thing i want to know is that how do i foce my compiler to use a specific set of headers and to ignore the others.?

Umm... these look like the headers for your kernel. Which is completely unrelated.

well that was the thing i messed up with earlier.

and i just reinstalled the new ones and every thing worked.

uhmmm, Hi guys...I know this seems a bit embarrassing but after you compiled a cpp program, how do you run it?

ummm, my apologies...researched it in the internet and found out how it works :

./Hello

thanx again...