您可以使用

You can use the isspace function in a loop to check if all characters are whitespace:

int is_empty(const char *s) {
  while (*s != '\0') {
    if (!isspace((unsigned char)*s))
      return 0;
    s++;
  }
  return 1;
}

如果任何字符不是空格(即行不为空)，则此函数将返回0，否则返回1.

This function will return 0 if any character is not whitespace (i.e. line is not empty), or 1 otherwise.