From mboxrd@z Thu Jan  1 00:00:00 1970
From: Art Haas <arthur.haas@westgeo.com>
To: help-gcc@gnu.org
Subject: Re: math.h prob
Date: Wed, 03 Nov 1999 08:27:00 -0000
Message-id: <lrwvrzefty.fsf@yoda.wg.waii.com>
References: <38204719.FD2DC371@clinmed.gla.ac.uk>
X-SW-Source: 1999-11/msg00011.html

Dave Brennan <9147261b@clinmed.gla.ac.uk> writes:

> Hi,
> 
> I am having problems using maths functions. e.g if I have the program
> 
> #include <stdio.h>
> #include <math.h>
> 
> main()
> {
> double x;
> scanf("%lf",&x);
> printf("x = %lf",sqrt(x));
> }
> 
> and try to compile it using,
> 
> gcc -o test mattest.c
> 
> I get the following error:
> 
> Undefined                       first referenced
>  symbol                             in file
> sqrt                                /var/tmp/cc9Eay_r1.o
> ld: fatal: Symbol referencing errors. No output written to test
> 

You need to link in the math library ...

% gcc -o test mattest.c -lm

-- 
###############################
# Art Haas
# (713) 689-2417
###############################

From mboxrd@z Thu Jan  1 00:00:00 1970
From: Art Haas <arthur.haas@westgeo.com>
To: help-gcc@gnu.org
Subject: Re: math.h prob
Date: Tue, 30 Nov 1999 23:28:00 -0000
Message-ID: <lrwvrzefty.fsf@yoda.wg.waii.com>
References: <38204719.FD2DC371@clinmed.gla.ac.uk>
X-SW-Source: 1999-11n/msg00011.html
Message-ID: <19991130232800.Z_eZ1jLE2qzZ9fZhaJBPj0AHe15GQRyvd_Y2qnWQDx4@z>

Dave Brennan <9147261b@clinmed.gla.ac.uk> writes:

> Hi,
> 
> I am having problems using maths functions. e.g if I have the program
> 
> #include <stdio.h>
> #include <math.h>
> 
> main()
> {
> double x;
> scanf("%lf",&x);
> printf("x = %lf",sqrt(x));
> }
> 
> and try to compile it using,
> 
> gcc -o test mattest.c
> 
> I get the following error:
> 
> Undefined                       first referenced
>  symbol                             in file
> sqrt                                /var/tmp/cc9Eay_r1.o
> ld: fatal: Symbol referencing errors. No output written to test
> 

You need to link in the math library ...

% gcc -o test mattest.c -lm

-- 
###############################
# Art Haas
# (713) 689-2417
###############################