一个gcc sqrt函数bug？

Question

以下程序无法在gcc中编译.但它与g ++和MSC++的.c扩展编译正常.

#include <math.h>
#include <stdio.h>

int main()
{
  double t = 10;
  double t2 = 200;

  printf("%lf\n", sqrt(t*t2));

  return 0;
}

我的系统是CentOS,版本信息.

> gcc --version
gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

错误信息:

> gcc test.c
/tmp/ccyY3Hiw.o: In function `main':
test.c:(.text+0x55): undefined reference to `sqrt'
collect2: ld returned 1 exit status

这是一个错误吗？

任何人都可以为我做测试吗？

Answer 1

你有没有连接数学库？

gcc -lm test.c -o test