如何增加一个循环中的IP地址？ [C] [英] How to increment an IP address in a loop? [C]

问题描述

我知道，对于大多数人来说，这很简单，但是我正在尝试在一个循环中以+1递增一个ip地址。

示例：

$ p $ for（double ip = 1.1.1.1; ip <1.1.1.5; ip ++）
{
printf（ ％f，ip）;





$ b基本上我所要做的就是增加一个IP for循环。
我不知道什么类型的变量来存储IP，不知道如何增加它。
当我运行程序时，出现一个错误，说明这个数字有太多的小数点。
我也看到在互联网上，你必须存储IP的字符数组，但你不能增加一个字符数组（我知道）。
我应该存储哪个变量类型的IP /我该如何处理这个问题？感谢您。

解决方案

天真的实现（no inet_pton ）会使用户4数字并将它们打印到 char 数组中

  #include< stdio.h中> 
 $ b int int_inc（int * val）{
 if（* val == 255）{
（* val）= 0; 
返回1; 
} 
 else {
（* val）++; 
返回0; 
 
 
 
 int main（）{
 int ip [4] = {0}; 
 char buf [16] = {0}; 
 
 while（ip [3] <255）{
 int place = 0; 
 while（place< 4& inc_ip（& ip [place]））{
 place ++; 
} 
 snprintf（buf，16，％d。％d。％d。％d，ip [3]，ip [2]，ip [1]，ip [0]）; 
 printf（％s \ n，buf）; 
 
 
 
 
 
 $ b编辑：一个由alk创建的新实现 p> 
 
 
  struct ip_parts {
 uint8_t vals [4]; 
}; 
 
 union ip {
 uint32_t val; 
 struct ip_parts部分; 
}; 
 
 int main（）{
 union ip ip = {0}; 
 char buf [16] = {0}; 
 
 while（ip.parts.vals [3] <255）{
 ip.val ++; 
 snprintf（buf，16，％d。％d。％d。％d，ip.parts.vals [3]，ip.parts.vals [2]，
 ip.parts。瓦尔斯[1]，ip.parts.vals [0]）; 
 printf（％s \ n，buf）; 
} 
} 
  
 
I know this is pretty simple for most of you but I am trying to increment an ip address by +1 in a loop.

Example:
for(double ip = 1.1.1.1; ip < 1.1.1.5; ip++)
{
printf("%f", ip);
}
Basically all I am trying to do is increment the ip by +1 in a for loop.
I don't know what type of variable to store the ip in and don't know how to increment it.
Whenever I run the program I get an error saying that the number has too many decimal points.
I've also seen on the internet that you have to store ip's in a character array, but you cannot increment a character array (that I know of).
What variable type should I store the ip in/how should I approach this? Thank you.
解决方案
A naive implementation (no inet_pton) would user 4 numbers and print them into a char array
#include <stdio.h>

int inc_ip(int * val) {
    if (*val == 255) {
        (*val) = 0;
        return 1;
    }
    else {
        (*val)++;
        return 0;
    }
}   

int main() {
    int ip[4] = {0};
    char buf[16] = {0};

    while (ip[3] < 255) {
        int place = 0;
        while(place < 4 && inc_ip(&ip[place])) {
            place++;
        }
        snprintf(buf, 16, "%d.%d.%d.%d", ip[3],ip[2],ip[1],ip[0]);
        printf("%s\n", buf);
    }
}
*Edit: A new implementation inspired by alk
struct ip_parts {
    uint8_t vals[4];
};

union ip {
    uint32_t val;
    struct ip_parts parts;
};

int main() {
    union ip ip = {0};
    char buf[16] = {0};

    while (ip.parts.vals[3] < 255) {
        ip.val++;
        snprintf(buf, 16, "%d.%d.%d.%d", ip.parts.vals[3],ip.parts.vals[2],
                                        ip.parts.vals[1],ip.parts.vals[0]);
        printf("%s\n", buf);
    }
}


                        
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