gcc in linux

[Fan Zhang]

Hi again,

I am new to compiling C programs in Linux/Unix. I wanted to compile a
program by using gcc, but it turned out that gcc does not know where to
locate the library being called.

The program is as follows,

#include <math.h>
int main()
{
double ss;
double ff;
ss=1.0;
ff=sin(ss);
printf("%6.4f\n ",ff);
return 0;
}

The error message is,

/tmp/ccIV3yAb.o: In function `main':
/tmp/ccIV3yAb.o(.tex t+0x1e): undefined reference to `sin'

The command I used to compile is
gcc test.c

Could anyone please let me know where I did wrong? Thanks!

Fan

[Nils O. Selåsdal]

Re: gcc in linux

Fan Zhang wrote:
[color=blue]
> The error message is,
>
> /tmp/ccIV3yAb.o: In function `main':
> /tmp/ccIV3yAb.o(.tex t+0x1e): undefined reference to `sin'
>
> The command I used to compile is
> gcc test.c
>
> Could anyone please let me know where I did wrong? Thanks![/color]
You need to link with the math library which is called libm
so,
gcc test.c -lm
comp.os.linux.d evelopment.apps or comp.unix.progr ammer
is probably more appropriate for this Q though.

[Arthur J. O'Dwyer]

Re: gcc in linux


On Tue, 12 Oct 2004, Fan Zhang wrote:[color=blue]
>
> /tmp/ccIV3yAb.o: In function `main':
> /tmp/ccIV3yAb.o(.tex t+0x1e): undefined reference to `sin'
>
> The command I used to compile is
> gcc test.c[/color]

This is practically word-for-word a FAQ.

http://www.eskimo.com/~scs/C-faq/q14.3.html

Read the whole thing.

-Arthur

[E. Robert Tisdale]

Re: gcc in linux

Fan Zhang wrote:[color=blue]
>
> I am new to compiling C programs in Linux/Unix.
> I wanted to compile a program by using gcc
> but it turned out that gcc does not know
> where to locate the library being called.
>
> The program is as follows,
>
> #include <math.h>
> int main()
> {
> double ss;
> double ff;
> ss=1.0;
> ff=sin(ss);
> printf("%6.4f\n ",ff);
> return 0;
> }
>
> The error message is,
>
> /tmp/ccIV3yAb.o: In function `main':
> /tmp/ccIV3yAb.o(.tex t+0x1e): undefined reference to `sin'
>
> The command I used to compile is
> gcc test.c
>
> Could anyone please let me know where I did wrong? Thanks![/color]

gcc test.c -lm

[Brian Gough]

Re: gcc in linux

"Fan Zhang" <fanzhang@sas.u penn.edu> writes:
[color=blue]
> I am new to compiling C programs in Linux/Unix. I wanted to compile a
> program by using gcc, but it turned out that gcc does not know where to
> locate the library being called. The command I used to compile is
> gcc test.c. Could anyone please let me know where I did wrong? Thanks![/color]

See http://www.network-theory.co.uk/docs...cintro_16.html
for information on linking with external libraries with gcc.

--
Brian Gough

Network Theory Ltd,
Publishing "An Introduction to GCC" --- http://www.network-theory.co.uk/gcc/

[Dan Pop]

Re: gcc in linux

In <87u0szvsd8.fsf @network-theory.co.uk> Brian Gough <bjg@network-theory.co.uk> writes:
[color=blue]
>"Fan Zhang" <fanzhang@sas.u penn.edu> writes:
>[color=green]
>> I am new to compiling C programs in Linux/Unix. I wanted to compile a
>> program by using gcc, but it turned out that gcc does not know where to
>> locate the library being called. The command I used to compile is
>> gcc test.c. Could anyone please let me know where I did wrong? Thanks![/color]
>
>See http://www.network-theory.co.uk/docs...cintro_16.html
>for information on linking with external libraries with gcc.[/color]

Except that the sin function has nothing to do with *any* external
library: it's part of the standard C library.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Dan.Pop@ifh.de
Currently looking for a job in the European Union

[Jack Klein]

Re: gcc in linux

On Tue, 12 Oct 2004 18:25:30 -0400, "Fan Zhang"
<fanzhang@sas.u penn.edu> wrote in comp.lang.c:
[color=blue]
> Hi again,
>
> I am new to compiling C programs in Linux/Unix. I wanted to compile a
> program by using gcc, but it turned out that gcc does not know where to
> locate the library being called.[/color]

Linux is not UNIX, UNIX is not Linux.
[color=blue]
> The program is as follows,
>
> #include <math.h>
> int main()
> {
> double ss;
> double ff;
> ss=1.0;
> ff=sin(ss);
> printf("%6.4f\n ",ff);
> return 0;
> }
>
> The error message is,
>
> /tmp/ccIV3yAb.o: In function `main':
> /tmp/ccIV3yAb.o(.tex t+0x1e): undefined reference to `sin'
>
> The command I used to compile is
> gcc test.c
>
> Could anyone please let me know where I did wrong? Thanks!
>
> Fan[/color]

Despite the fact that Linux is not UNIX, gcc on Linux continues the
old UNIX tradition of pretending that part of the standard C library
is not part of the standard C library.

UNIX elitists do not like to make things easy for the uninitiated,
unwashed masses, even when the reason for a particular piece of
stupidity has been obsolete for 20 years.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.l earn.c-c++

http://www.contrib.andrew.cmu.edu/~ajo/docs/FAQ-acllc.html

[Darklight]

Re: gcc in linux

Jack Klein wrote:
[color=blue]
> On Tue, 12 Oct 2004 18:25:30 -0400, "Fan Zhang"
> <fanzhang@sas.u penn.edu> wrote in comp.lang.c:
>[color=green]
>> Hi again,
>>
>> I am new to compiling C programs in Linux/Unix. I wanted to compile a
>> program by using gcc, but it turned out that gcc does not know where to
>> locate the library being called.[/color]
>
> Linux is not UNIX, UNIX is not Linux.
>[color=green]
>> The program is as follows,
>>
>> #include <math.h>
>> int main()
>> {
>> double ss;
>> double ff;
>> ss=1.0;
>> ff=sin(ss);
>> printf("%6.4f\n ",ff);
>> return 0;
>> }
>>
>> The error message is,
>>
>> /tmp/ccIV3yAb.o: In function `main':
>> /tmp/ccIV3yAb.o(.tex t+0x1e): undefined reference to `sin'
>>
>> The command I used to compile is
>> gcc test.c[/color][/color]

try this gcc -Wall -lm test.c