按照书上的例题写了两段代码
parta.c

#include <stdio.h>
void report_count ();
void accumulate (int k);
int count = 0;
int main (void)
{
    int value;
    register int i;
   

    printf ("Enter a positive integer (0 to quit):");
    while (scanf ("%d", &value) == 1 && value > 0)
    {
        ++count;
        for (i = value; i >= 0; i--)
        {
            accumulate (i);
        }
        printf ("Enter a positive integer (0 to quit):");
    }
    report_count ();
    system ("pause");
    return 0;
}

void report_count ()
{
    printf ("Loop executed %d times\n", count);
}

partb.c

#include <stdio.h>
extern int count;
static int total = 0;
void accumulate (int k)

void accumulate (int k)
{
    static int subtotal = 0;
   

    if (k <= 0)
    {
        printf ("loop cycle: %d\n", count);
        printf ("subtotal: %d; total: %d\n", subtotal, total);
        subtotal = 0;
    }
    else
    {
        subtotal += k;
        total += k;
    }
}

然后用gcc 12_parta.c 12_partb.c -o 12_part.exe编译，出现以下错误提示

12_partb.c: In function 'accumulate':
12_partb.c:7:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
 {
 ^
12_partb.c:21:1: error: expected '{' at end of input
 }
 ^

gcc下多文件编译是这么写吗？还是代码有问题？

partb.c

void accumulate (int k)-->>extern void accumulate (int k);

gcc parta.c -c parta.o
gcc partb.c -c partb.o
ld parta.o partb.o -o part

这是linux下的编译命令，win下的一样。不过，扩展名可能需要相应地改一下。