gets() is not taking input in C

Asked May 06 '15 at 09:38

Active May 06 '15 at 09:38

Viewed 67 times

Okay so I am writing this simple piece of code and I am just a beginner in C. This code compiles and runs as expected but when I get to the point where I must enter an address this code just skips the input, but when I use scanf in that place the code runs perfectly can anyone help me out?

SOURCE

#include<stdio.h>
#include<conio.h>

void main()
{
    struct student
    {
        int rn;
        long int phn;
        char name[50];
        char add[50];
    }s;

    char ans, filename[15];

    FILE *fp;
    printf("\n Enter File Name : ");
    gets(filename);
    fp=fopen(filename, "w");

    again:
    printf("\n Enter a name of a student : ");
    gets(s.name);
    printf("\n Enter his roll number : ");
    scanf(" %d ", &s.rn);
    printf("\n Enter his address : ");
    gets( s.add);
    printf("\n Enter his phone Number : ");
    scanf("%ld", &s.phn);
    fprintf(fp, "%s\t%d\t%s\t%ld\n", s.name, s.rn, s.add, s.phn);
    printf("\n Want to keep next record ? : ");
    fflush(stdin);
    scanf("%c", &ans);
    if(ans=='y'||ans=='Y')
    goto again;
    fclose(fp);
    getch();
}

I want a detailed explanation to this can anyone help me out?

asked May 06 '15 at 09:38

Naveen

What input is skipped? What's a realistic use case? – Eregrith May 06 '15 at 09:40
I cannot input the address instead phone number is asked! – Naveen May 06 '15 at 09:41
1

Add `int c;while((c=getchar())!='\n' && c!=EOF);` just before the `gets`. – Spikatrix May 06 '15 at 09:41
6

*Side note:* Don't use **goto**, it is bad practice and not needed. Use `... fp=fopen(filename, "w"); do { printf("\n Enter a name of a student : "); ... scanf("%c", &ans); } while (ans=='y' || ans=='Y'); fclose(fp); ...` – axiac May 06 '15 at 09:43
@CoolGuy why is it not working that way? – Naveen May 06 '15 at 09:43
2

`scanf("%c", &ans);` --> `scanf("%c%*c", &ans);` – BLUEPIXY May 06 '15 at 09:44
8

_Side note_ : [why-is-the-gets-function-so-dangerous-that-it-should-not-be-used?](http://stackoverflow.com/questions/1694036/why-is-the-gets-function-so-dangerous-that-it-should-not-be-used) – Dayal rai May 06 '15 at 09:44
3

*Side note:* don't use `void main` - it should be `int main` and `main` should have a `return` statement at the end. – Paul R May 06 '15 at 09:46
3

side note: always check the result of fopen(). – Peter Miehle May 06 '15 at 09:53
4

`fflush(stdin)` is undefined behaviour. – Jabberwocky May 06 '15 at 09:57
@BLUEPIXY wow amazing but why does that work can you explain – Naveen May 06 '15 at 10:03
3

remaining newline in input buffer. `%*c` consume it. – BLUEPIXY May 06 '15 at 10:04

gets() is not taking input in C

0 Answers0