File Handling Error in C

Question

I am learning file handling in C.I have this code but it is not accepting string as an input to write it to a file.Any help will be appreciated.

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

    int main(void)
    {
        FILE * fp1;
        fp1 = fopen("abc.txt","a+");
        if(fp1==NULL)
        {printf("An error occurred");
        }
        printf("Delete file?\n");


        int a,c;
        char name [20];
        int flag=1;
        int ch=1;
        while(flag!=0)
            {

                printf("Enter id input \n");

                scanf("%d",&a);
                fprintf(fp1,"\n%d\t",a);

                printf("Enter Name");
                gets(name);
                fputs(name, fp1);
                printf("Enter No \n");

        scanf("%d",&c);
        fprintf(fp1,"\t%d\t",c);



        printf("Write more then press 0 else 1");
        scanf("%d",&ch);
        if(ch==1)
            {
                flag=0;
            }
        }
        fclose(fp1);

    }

On running this code the code does not take an input after Enter Name and directly skips to Enter No.I want the output to be in a tabular form.

You should exit the program when `fp` is `NULL`. Also, indent your code properly so that it is easier for (other) humans to read. — Spikatrix, Jun 07 '15 at 14:45

score 2 · Answer 1 · answered Jun 07 '15 at 14:32

2

Use a getchar() after entering id because the \n of 1st scanf stays in buffer.

printf("Enter id input \n");
scanf("%d",&a);
getchar();

answered Jun 07 '15 at 14:32

Sourav Kanta

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score 1 · Accepted Answer · edited May 23 '17 at 10:26

When you enter a number for scanf("%d",&a);, you type in a number and press the Enter key. The scanf consumes the number and leaves the newline character ('\n') in the standard input stream (stdin). When the execution of the program reaches gets(name);, gets sees the newline character and consumes it, storing it in name.

Firstly, never use gets as it is dangerous as it doesn't prevent buffer overflows. Use fgets instead:

fgets(name, sizeof(name), stdin);

Secondly, you have to get rid of the newline character. You can do this by flushing the stdin. Or you can simply scan and discard the newline character just after reading the number from scanf by changing

scanf("%d",&a);

to

scanf("%d%*c",&a);

%*c scans and discards a character.

score 0 · Answer 3 · answered Jun 07 '15 at 15:05

gets() is deprecated, don't use it. you can still use scanf()... as for the tabulation...think it through.

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

int main(void)
{
    FILE* fp1;
    fp1 = fopen("abc.txt", "a+");

    if (fp1 == NULL) {
        printf("An error occurred");
    }

    int a, c;
    char name [20];
    int flag = 1;
    int ch = 1;

    while (flag != 0) {

        printf("Enter id input:\n");
        scanf("%d", &a);
        fprintf(fp1, "%d\t", a);

        printf("Enter Name:\n");
        scanf("%s", name);
        fprintf(fp1, "%s\t", name);

        printf("Enter No:\n");
        scanf("%d", &c);
        fprintf(fp1, "%d\n", c);

        printf("Again (0) or Exit(1) ?:\n");
        scanf("%d", &ch);

        if (ch == 1) {
            flag = 0;
        }
    }

    fclose(fp1);

    return 0;
}

File Handling Error in C

3 Answers3