Nsryjdtyk

I'm the novice and still learning C language. Currently, I'm having a problem with my code. The task is delete something in the file IO, by default there is some record in my txt file. The task is asking the user to input the which lines he/she would like to delete in txt file. However, the problem occurs:

1 )the c program still work in the first time, but the second, third time and below cannot work.(that mean just can delete lines in the first time)

I think it is a buffer problem, so I add many fflush codes, but still cant solve.

2) I would like to change my program into using a keyword to find the record and delete.User type the recordnum can delete whole item record. However, I have not idea how it works.

if someone can help me , I am very grateful and happy.
1)code is below :

#include<stdio.h> #include<stdlib.h>      

int main(){

FILE *fileptr1, *fileptr2, *fileptr3;

char filename[40]="itemrecord.txt";

char save;

int delete_line, temp = 1;

char reply;



printf("Enter file name: ");

scanf("%s", filename);



do{





//open file in read mode

fileptr1 = fopen(filename, "r");

if (fileptr1== NULL){

printf("open unsuccessful,file not exist"); 

exit(1);

}

save = getc(fileptr1);

while (save != EOF)

{

    printf("%c", save);

    save = getc(fileptr1);

}



//rewind

rewind(fileptr1);



fflush(stdout);

printf(" nn Enter line number of the line to be deleted <type 0 = not 

delete anything>:");

fflush(stdin);

scanf("%d", &delete_line);





//open new file in write mode

fileptr2 = fopen("copy.c", "w");

save = 'a';

while (save != EOF)

{

    save = getc(fileptr1);

    //except the line to be deleted

    if (temp != delete_line)

    {

        //copy all lines in file replica.c

        putc(save, fileptr2);

    }

    if (save == 'n')

    {

        temp++;

    }

   }



fclose(fileptr1);

fclose(fileptr2);

remove(filename);

//rename the file replica.c to original name

rename("copy.c", filename);

fflush(stdout);

printf("nThe contents of file after being changed are as follows:n");



fileptr1 = fopen(filename, "r");

save = getc(fileptr1);

while (save != EOF)

{

    printf("%c", save);

    save = getc(fileptr1);

}

fflush(stdout);

fflush(stdin);

fclose(fileptr1); 



 printf("nn Delete anther item?<y/n>: ");

 scanf("%c",&reply);  



 }while(reply=='y' || reply=='Y');

  return 0;

  }

Result :

Enter file name:itemrecord

mary 1 123

sam  2 124

bob  3 125



Enter line number of the line to be deleted<type 0=not delete anything>:1



The contents of file after being changed are as follows:

sam  2 124

bob  3 125



Delete other record?<y/n>:y

sam  2 124

bob  3 125



Enter line number of the line to be deleted<type 0=not delete anything>:1



The contents of file after being changed are as follows:

sam  2 124

bob  3 125   



Delete other record?<y/n>:n



//second time doesn't work.//

I'm sorry for the long code and long question, but I'm so confusing...

2)if my record into

Mary

1

123



sam  

2 

124



bob  

3 

125

SO how I can type 'Mary' delele whole record item? something like that...

sam  

2 

124



bob  

3 

125

Try this

int delete_line, temp;

char reply;



printf("Enter file name: ");

scanf("%s", filename);



do{

    temp = 1;

    ....

I hope this helps.