0
典型的初學者電話簿程序，試圖添加讀寫文件功能。這不是編得很好，但在我執行的是函數7或8，我的ErrorHandler返回「無效的參數」無效的參數讀寫文件
編輯*整個事情更新的代碼，其中包括了一些修復：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct phonebook
{
char cFirstName[20];
char cLastName[20];
char PhoNo[20];
} pb;
//function prototypes
void AddContact (pb *);
void DeleteContact (pb *);
void ShowContacts (pb *);
void FindContact (pb *);
void RandContact (pb *);
void FindContact (pb *);
void DeleteAll (pb *);
void Read (pb *);
void Write (pb *);
char FileName[100];
FILE *pRead;
FILE *pWrite;
int counter = 0;
main()
{
pb *phonebook;
phonebook = (pb*) malloc(sizeof(pb)*1);
int iChoice = 0;
while (iChoice <= 8)
{
printf("\n-Choose an option- \n");
printf("\n\t(1)\tAdd Contact");
printf("\n\t(2)\tDelete Contact");
printf("\n\t(3)\tShow All Contacts");
printf("\n\t(4)\tSearch for a Contact");
printf("\n\t(5)\tRandom Contact");
printf("\n\t(6)\tDelete All Contacts");
printf("\n\n\t(7)\tWrite contacts to file");
printf("\n\t(8)\tRead contacts from file");
printf("\n\n\t(9)\tExit\n\n\t");
scanf("%d", &iChoice);
if (iChoice == 1)
{
AddContact(phonebook);
}
if (iChoice == 2)
{
DeleteContact (phonebook);
}
if (iChoice == 3)
{
ShowContacts(phonebook);
}
if (iChoice == 4)
{
FindContact(phonebook);
}
if (iChoice == 5)
{
RandContact(phonebook);
}
if (iChoice == 6)
{
DeleteAll(phonebook);
}
if (iChoice == 7)
{
Write(phonebook);
}
if (iChoice == 8)
{
Read(phonebook);
}
if (iChoice == 9)
{
free(phonebook);
return 0;
}
} //end while
} //end main
//function definitions
//add contact
void AddContact (pb * phonebook)
{
counter++; //counter incremented for each entry
realloc(phonebook, sizeof(pb)); //realloc with every new contact
printf("\nFirst Name: ");
scanf("%s", phonebook[counter-1].cFirstName);
printf("Last Name: ");
scanf("%s", phonebook[counter-1].cLastName);
printf("Phone Number: ");
scanf("%s", phonebook[counter-1].PhoNo);
printf("\n\tContact added\n");
}
//delete contact
void DeleteContact (pb * phonebook)
{
int x = 0;
char scrapcFirstName[20]; //strings for deleting original strings
char scrapcLastName[20];
char nullStr[20] = {"\0"};
printf("\nFirst name: ");
scanf("%s", scrapcFirstName);
printf("Last name: ");
scanf("%s", scrapcLastName);
//compare strings
for (x = 0; x < counter; x++)
{
if (strcmp(scrapcFirstName, phonebook[x].cFirstName) == 0)
{
for (x = 0; x < counter; x++)
{
if (strcmp(scrapcLastName, phonebook[x].cLastName) == 0)
{
strcpy(phonebook[x].cFirstName, nullStr);
strcpy(phonebook[x].cLastName, nullStr);
strcpy(phonebook[x].PhoNo, nullStr);
}//end if
else
{
printf("Invalid Input");
}
}//end for
}//end if
} // end for
counter--; // Contact deleted, update counter
printf("Contact Deleted\n");
}
// show phonebook
void ShowContacts (pb * phonebook)
{
int x = 0;
printf("\nPhonebook:\n\n ");
for(x = 0; x < counter; x++)
{
printf("\n(%d)\n", x+1);
printf("Name: %s %s\n", phonebook[x].cFirstName, phonebook[x].cLastName);
printf("Number: %s\n", phonebook[x].PhoNo);
} //end for
}
//Find a specific contact
void FindContact (pb * phonebook)
{
int x = 0;
char TempFirstName[20];
char TempLastName[20];
printf("\nWho are you looking for?");
printf("\n\nFirst Name: ");
scanf("%s", TempFirstName);
printf("Last Name: ");
scanf("%s", TempLastName);
for (x = 0; x < counter; x++)
{
if (strcmp(TempFirstName, phonebook[x].cFirstName) == 0)
{
if (strcmp(TempLastName, phonebook[x].cLastName) == 0)
{
printf("\n%s %s \n%s\n", phonebook[x].cFirstName, phonebook[x].cLastName, phonebook[x].PhoNo);
}
}
}
}
//show a random contact
void RandContact (pb * phonebook)
{
int iRand = 0;
srand(time(NULL));
iRand = rand() % counter;
int x = iRand;
printf("\n%s %s\n", phonebook[x].cFirstName, phonebook[x].cLastName);
printf("%s\n", phonebook[x].PhoNo);
}
//delete all
void DeleteAll (pb * phonebook)
{
int x = 0;
char nullStr[20] = {'\0'};
for (x = 0; x < counter; x++)
{
strcpy(phonebook[x].cFirstName, nullStr);
strcpy(phonebook[x].cLastName, nullStr);
strcpy(phonebook[x].PhoNo, nullStr);
--counter;
}
printf("Contacts have been wiped.\n");
}
void Read(pb * phonebook)
{
FILE *pRead;
char name[256];
printf("File to read: ");
gets(name);
pRead=fopen(name,"a");
if(pRead != NULL)
{
printf("Contact List");
while(!feof(pRead)){
fread(phonebook, sizeof (struct phonebook), 1, pRead);
fclose(pRead);
if (!feof(pRead)){
fread(phonebook, sizeof (struct phonebook), 1, pRead);
fclose(pRead);
}
}
}
else{
goto ErrorHandler;
}
exit(EXIT_SUCCESS);
ErrorHandler:
perror("The following error occured");
exit(EXIT_FAILURE);
}
void Write(pb * phonebook)
{
FILE *pWrite;
char name[256];
printf("File to write:");
gets(name);
pWrite=fopen(name,"a");
if(pWrite != NULL)
{
fwrite(phonebook, sizeof (struct phonebook), 1, pRead);
fclose(pWrite);
}
else{
goto ErrorHandler;
}
exit(EXIT_SUCCESS);
ErrorHandler:
perror("The following error occured");
exit(EXIT_FAILURE);
}
它仍然給我同樣的錯誤，「無效的參數」
在'Read（）'中，完全混淆了正在使用哪個文件指針。另外，我沒有看到'fclose（）'，'feof（）'用得不好。 – unwind
你是什麼意思？我能更好地使用feof？它正在等待執行條件，直到文件結束。 –
這經常被提及，我應該尋找一個參考。在嘗試讀取之前，不能使用'feof（）'檢測「文件結束」*，並且因爲您已到達文件結尾而無法檢測。它應該被用來弄清楚爲什麼失敗的東西沒有阻止它失敗。只讀，直到閱讀失敗。 – unwind