c - 为什么我的 strcpy() 不覆盖整个字符串并保留最后一个 char [] 中的字符？

Question

我有一个简单的方法，它接受文件名和指向链接列表的指针。看起来链表没有什么问题。但是，我注意到由于某种原因， strcpy 似乎无法覆盖以前存在的字符串。每次我覆盖字符数组时，副本都会变得越来越糟。 为什么 strcpy 保留以前的数据？

void readFile(struct record ** recordArray, char inputArray [])
{

struct record ** temp = recordArray;
char theString [100];
char characterInput;
int counter = 0;
counter  = 0;
FILE * infile = fopen(inputArray, "r");

char name [100];
char address [100];
int yearofbirth;
char telno [20];

int target = 0;
/*
0 name
1 address
2 yearofbirth
3 telno
*/

/*If the file exists*/
if (infile != NULL)
{ 
   while (characterInput != EOF)
   {
        characterInput = fgetc(infile);

        if (characterInput == '\n')
        {
            theString[counter] = '\0';

            if (target == 0)/*name*/
            {
                strcpy(name, theString);
                counter = 0;
                target++;
            }
            else if (target == 1) /*address*/
            {
                strcpy(address, theString);
                counter = 0;
                target++;
            }
            else if (target == 2) /*yearofbirth*/
            {
                yearofbirth = atoi(theString);
                counter = 0;
                target++;
            }
            else if (target == 3) /*telephone number*/
            {
                strcpy(telno, theString);
                counter = 0;
                target = 0;
                addRecord(temp, name, address, yearofbirth, telno);
            }
        }
        else /*if the character is not a null line ie its a regular character*/
        {
          theString[counter] = characterInput;  
          counter++;   
        }
   } 
}
else
{
    printf("Error: There has to be a file named: %s\n", inputArray);
}
fclose(infile);

}

输入:

bill
firstaddress
9119398644
1993

tim
birch st.
7567115
1980

roger
wood st drive
4830382
1909

输出:

Name: bill
Address: firstaddress
Birthyear: 529464052
Telephone Number: 1993398644ss

Name: tim3398644ss
Address: birch st.4ss
Birthyear: 7567115
Telephone Number: 1980115t.4ss

Name: timmy15t.4ss
Address: wood st drive
Birthyear: 4830382
Telephone Number: 1909382 drive

编辑:

这是最终运行的代码。谢谢大家。

void readFile(struct record ** recordArray, char inputArray [])
{

struct record ** temp = recordArray;
char theString [100];
char characterInput;
int counter = 0;
counter  = 0;
FILE * infile = fopen(inputArray, "r");

char name [100];
char address [100];
int yearofbirth;
char telno [20];

int target = 0;
/*
0 name
1 address
2 yearofbirth
3 telno
*/

/*If the file exists*/
if (infile != NULL)
{ 
   while (characterInput != EOF)
   {
        characterInput = fgetc(infile);

        if (characterInput == '\n')
        {
            theString[counter] = '\0';

            if (target == 0)/*name*/
            {
                strcpy(name, theString);
                counter = 0;
                target++;
            }
            else if (target == 1) /*address*/
            {
                strcpy(address, theString);
                counter = 0;
                target++;
            }
            else if (target == 2) /*yearofbirth*/
            {
                yearofbirth = atoi(theString);
                counter = 0;
                target++;
            }
            else if (target == 3) /*telephone number*/
            {
                strcpy(telno, theString);
                counter = 0;
                target = 0;
                addRecord(temp, name, address, yearofbirth, telno);
            }
        }
        else /*if the character is not a null line ie its a regular character*/
        {
          theString[counter] = characterInput;  
          counter++;   
        }
   } 
}
else
{
    printf("Error: There has to be a file named: %s\n", inputArray);
}
fclose(infile);
}

Answer 1

您需要使用 '\0' 终止输入字符串。

更改:

    if (characterInput == '\n')
    {
        if (target == 0)/*name*/
        {
            ...

至:

    if (characterInput == '\n')
    {
        theString[counter] = '\0';  // terminate input string

        if (target == 0)/*name*/
        {
            ...