我正在尝试实现一个保存系统，它允许我保存用户输入的用户在switch语句中输入的“数据包”结构的数据。输入的每条记录都存储在通过纯文本行分隔的单个文件中。它还应该提示用户他们想要命名文件，然后程序应该指示已经保存到文件的记录数，最后如果没有输入保存文件的名称，它应该返回主菜单。 / p>
从底部的void save函数可以看到，我试图实现这个保存系统，但是当我运行程序并选择S将记录保存到文件时，它只是在我输入一个名称后崩溃文件名。所以如果有人能帮助我，那就太好了。
更新
通过调试器运行程序后，我得到以下错误
更新
修正了错误的错误，但是在输入文件的文件名时程序也会崩溃，而文件也会保存数据。
#include <stdio.h> //library including standard input and output functions
#include <stdlib.h> //library including exit and system functions used below
#include <string.h> //library including string functions used
struct packet{
int source;
int destination;
int type; // Varibles for the structure
int port;
char data[50];
char * filename;
};
void save(int, struct packet*); //function to save the records stored to a file
int main ()
{
struct packet s[50]; //Array for structure input
char choice;
int NetworkPacket = 0, ii = 0;
int recordCount = 0;
struct packet *records;
struct packet *temp;
records = malloc(sizeof(struct packet));
do{
system("cls");
puts("Please enter an option:\n");
puts("'A' Add a packet:\n");
puts("'D' to Display the Packet List:\n"); // The Menu system
puts("'S' to Save the Packets to a file:\n");
puts("'C' to Clear the list of current saved packets:\n");
puts(" or X to exit the program...\n");
//wait for user input
scanf("%c", &choice); //take the first char of user input and assing the value to
//the variable choice using the address of (&) the variable
if(choice == '\n') //check to see that the character is not \n left over from the
scanf("%c", &choice); //previous choice made, if it is then we need to scan the input again
switch (choice)
{
case 'A': system("cls"); //clear the screen
if(NetworkPacket==50)
{
printf("No more network packets can be added"); // if statement giving the limit of 50 packets allowed to be added
getch(); // User must press a key to continue
continue;
}
else{
printf("\n****Adding a packet*****\n");
printf("Where is the packet from?\n");
scanf("%i", &s[NetworkPacket].source);
printf("Where is the packet going?\n");
scanf("%i", &s[NetworkPacket].destination);
printf("What type is the packet?\n");
scanf("%i", &s[NetworkPacket].type); // collecting the data of the packet inputted by the user
printf("What is the packet's port?\n");
scanf("%i", &s[NetworkPacket].port);
printf("Enter up to 50 characters of data.\n");
scanf("%s", s[NetworkPacket].data);
NetworkPacket++;
}break;
case 'D': system("cls"); //clear the screen
printf("\nDisplaying Infomation\n");
if(NetworkPacket==0) // if statement stating to the user no records are shown if none are avalible
{
printf("no records yet, Please press any key to revert back to the main menu\n");
getch(); // User must press a key to continue
continue;
}
else{
for(ii = 0; ii < NetworkPacket; ii++)
{ // adds a 1 onto the NetworkPacket counter keeping a tally on the number of records stored.
printf("\nSource: %d", s[ii].source);
printf("\nDestination: %d", s[ii].destination );
printf("\nType : %d", s[ii].type);// if statement giving the limit of 50 packets allowed to be added
printf("\nPort : %d", s[ii].port);
printf("\nData: %s\n---\n", s[ii].data);
}getch();
} break;
case 'S':
system("cls"); //clear the screen
save(NetworkPacket, records); //S was chosen so use the Save function
break; //the while condition is True so break the switch and loop around
case 4: break;
case 5: break;
default:system("cls"); printf("%c is not an option\n Try again...\n", choice); // this message is shown if user doesn't input of one the case statment letters.
}
}while(choice!='X' ); // exits the program
return 0;
}
void save(int rCount, struct packet *NetworkPacket){
FILE *recordFile; //file handle
char fileName[30] = { '\0'}; //string to store the file name
int i;
puts("Enter a filename to save the records :"); //ask the user for the filename
scanf("%s", fileName); //store the filename: data input should be checked
//here in your program
//try and open the file for writing and react accordingly if there is a problem
if((recordFile = fopen(fileName,"w"))==NULL){
printf("Couldn't open the file: %s\n",fileName);
exit(1);
}
else{ //the file opened so print the records array of packets to it
for(i=0;i<rCount;i++){
fprintf(recordFile,"%04d %04d %04d %04d %s\n",
NetworkPacket[i].source,
NetworkPacket[i].destination,
NetworkPacket[i].type,
NetworkPacket[i].port,
NetworkPacket[i].port,
NetworkPacket[i].data);
}
fclose(recordFile); //close the file
}
}
答案 0 :(得分：2)
case 'S': break; <---- you have a break just after the case definition try remove it
system("cls"); //clear th
除了'S'以外的其他情况？
以及您应该使用fgets代替scanf的建议。
答案 1 :(得分：0)
好的我已经弄清楚如何修复调试器错误，但主要问题是，当提示我为保存文件选择文件名时，程序崩溃
line 5: warning: "struc packet" declared inside parameter list
所以这发生了，因为我在一个函数中声明了struc数据包而没有首先声明什么是struc数据包。但现在已经修复了
line 22: warning: assignment makes integer from pointer without a cast
我通过给它指向Struc数据包数据
的地址的实际指针来解决这个问题line 89: warning: passing arg 2 of 'save' makes pointer from integer without a cast
与上述相同的解决方案。
我现在将更新代码