字符串/分段故障 [英] String / segmentation fault

问题描述

/*                                                                           
  Program to calculate trip and plan flights                                 
*/
#define TRIP 6
#define NAMEMAX 40
#define DEST 1

#include <stdio.h>
#include <string.h>


int main(void)
{
  int i, trip_num, row, col;
  char travel_name[TRIP][DEST],
    dest_in[1];


  printf("Please enter the number of trips:");
  scanf("%d", &trip_num);

  while (trip_num > TRIP)
    {
      printf("Invalid number of trip. (Min of 3 trips and Max 6 trips).\n");\
  /*input number of trips*/
      printf("Please enter the number of trips:");
      scanf("%d", &trip_num);
      if (trip_num < TRIP)
        printf("Valid trip number. Please proceed to enter destination code.\
\n");
    }

  for (i=0; i < trip_num ; i++)

    {
      printf("Please enter name of destination(Note: use _ to for spaces in \
name):\n");
      scanf("%s", &dest_in);
      if (strlen(dest_in) < NAMEMAX)
        strcpy(travel_name[i],dest_in);
   /*   else (strlen(dest_in) > NAMEMAX) */



  for (row = 0; row < trip_num; row++)
    {
      for (col=0; col < DEST; col++)
        printf("Trip#:%d travel_name:%s \n", row+1, travel_name[row][col]);
    }

  return 0;
}

我试图让用户把一个名字作为字符串，并将其存储如果名称是40个字符以内，但它给了我一个分段错误

I'm trying to get the user to put in a name as string and store it if the name is 40 character or less but its giving me a segmentation fault

推荐答案

有许多与你的code的问题。

There are lots of problems with your code.

1. scanf函数（％S，＆安培; dest_in）将读到一个字符串转换成 dest_in 这可能会溢出你的缓冲区因为没有大小说明。考虑将其更改为 scanf函数（％99秒，dest_in）让你读99个字符最多，+ 1为空终止为100（阵列大小）。此外，也没有必要使用＆放大器; 运营商在这里

1. scanf("%s", &dest_in) will read a string into dest_in which could potentially overflow your buffer because there is no size specifier. Consider changing it to scanf("%99s", dest_in) so you read 99 characters maximum, + 1 for the null terminator which is 100 (your array size). Also, there is no need to use to & operator here.

travel_name [I] [0] = dest_in [100]; 您正在访问的字符是dest_in的边界之外。你应该访问的唯一指标为0。

travel_name[i][0]=dest_in[100]; You are accessing a character that is outside the bounds of dest_in. The only index you should access is 0.

的printf（旅行＃：％d个travel_name：％S \\ n，排+ 1，travel_name [行] [COL]）; 您$ ç$ C说，你要打印的字符串。 printf的去寻找一个指向一个字符数组，但 travel_name [行] [COL] 是单个字符。

printf("Trip#:%d travel_name:%s \n", row+1, travel_name[row][col]); Your code says that you want to print a string. printf goes looking for a pointer to a character array but travel_name[row][col] is a single character.

而（trip_num＆GT; TRIP）。你告诉用户在3到6之间输入一个号码，但你不检查，如果输入小于3。

while (trip_num > TRIP). You tell the user to enter a number between 3 and 6 but you don't check if the input is less than 3.

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