Re: problems with pow( ) in gcc

[Viktor Pavlenko <vp@example.com>]

>>>>> On Tue, 30 Jan 2001 22:59:27 -0600, David Eduardo Gomez Noguera <davidgn@example.com> said:

    DEGN> On Wed, 31 Jan 2001 12:30:54 +0900
    DEGN> Hector Akamine <akamine@example.com> was chatting
    DEGN> the other day about l and said:

    DEGN> The problem is "pow" is not declared on math.h (at least it
    DEGN> doesnt appeara on my header files either, and its redhat's
    DEGN> glibc.  dont know if redhat screw something, or if glibc is
    DEGN> laggin it.

bits/mathcalls.h contains the pow's prototype and is included by
math.h. There's some #define magic going on there.

math.h:

/* The file <bits/mathcalls.h> contains the prototypes for all the
   actual math functions.  These macros are used for those prototypes,
   so we can easily declare each function as both `name' and `__name',
   and can declare the float versions `namef' and `__namef'.  */

    DEGN> pow does appear in the info pages, but it doesnt say what header it requires.

pow man page here (RH 6.2) does say you have to include math.h

Viktor



    >> I was trying to compile this simple program. The gcc compiler is the one
    >> included in Vine Linux 2.0
    >> 
    >> ------- program begin ----------
    >> 
    >> #include <stdio.h>
    >> #include <math.h>
    >> 
    >> int main() {
    >> double maxi;
    >> 
    >> printf("pow test:");
    >> maxi = pow (2.0, 5.0 );
    >> printf("%f\n",maxi);
    >> 
    >> }
    >> 
    >> ------- program end ----------
    >> 
    >> But the compiler throws the following error:
    >> 
    >> ------- begin --------
    >> $ gcc -o test test.c
    >> 
    >> 
    >> /tmp/ccfCPb5f.o: In function `main':
    >> /tmp/ccfCPb5f.o(.text+0x22): undefined reference to `pow'
    >> collect2: ld returned 1 exit status
    >> 
    >> -------- end ---------
    >> 
    >> What am I doing wrong?
    >> 
    >> 
    >> Thanks in advance
    >> 
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