A fool question.

mgjrr

I am new with linux.There're some trouble with my first program.Can Anyone give me some clue?
::::
#include<stdio.h>
#include<math.h>

int main(void)
{
        double pi=M_PI;
        double pisqrt;
        long i;

        for (i=0;i<10000000;++i)
        {
                pisqrt = sqrt(pi);
        }
        return 0;
}

The erro message is"
/tmp/ccr8tIwR.o(.text+0x3c): In function `main':
: undefined reference to `sqrt'
collect2: ld returned 1 exit status
"
What's the matter?

原始人

gcc a.c -o a -lm
告诉编译器要连接数学库

mgjrr

It works.
Thank you,I just want to kiss you.