c - 总结命令行

Question

非常简单，我正在尝试对命令行中输入的所有整数求和。总和实际上有效，如果我以“1 1 1 1 ”输入启动程序，总和将增加四次。问题是 sum 被初始化为某个非常大的数字 (4293283588)。这是为什么？

int main(int argc, char*argv[])
{
  int a = 0;
  int sum = 0;
  size_t i = 0;

  for (i=0; i<argc; i++)
  {
     a = atoi(argv[i]);
     sum = sum + a;
     printf("%ld\n", sum);
  }

  return 0;
}

Answer 1

argv[0] 可能是可执行文件的名称。来自标准:

5.1.2.2.1 Program startup

....

If the value of argc is greater than zero, the string pointed to by argv[0] represents the program name; argv[0][0] shall be the null character if the program name is not available from the host environment. If the value of argc is greater than one, the strings pointed to by argv[1]
through argv[argc-1] represent the program parameters.

尝试

for (i=1; i<argc; i++)

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此外，正如 @BLUEPIXY 指出的那样，%ld 假定类型为 long。因此，要么将其更改为 %d，要么使用 long sum。