how to take input of two string?

Question

#include <stdio.h>
#include<stdlib.h>
#include <string.h>
int main(void) {
    char a[1001];
    int t,i;
    scanf("%d",&t);

    while(t--)
    {
        fflush(stdin);
        gets(a);
        printf("%d\t",t);
        puts(a);

    }
    return 0;
}

Input:

2 
die another day.
i'm batman.

Ouput:

1   
0   die another day.

Expected Output:

1    die another day.
0    i'm batman.

Anyone please help how to accept more than one string without any bugs. I am able to see after entering 2 my gets is taking newline as first string and later second string properly. Thanks in advance

Technically `fflush(stdin)` is undefined behavior. It's not supported on all systems and platforms. — Some programmer dude, Apr 17 '14 at 14:17
Any idea to make the program work on almost compilers properly?Including online compilers. — tech_boy, Apr 17 '14 at 14:18

score 2 · Accepted Answer · edited May 23 '17 at 11:57

2

Stop using scanf() of stdin to read input. Never call fflush(stdin); either, but if you stop using scanf() you will no longer want to.

Read whole lines using fgets() into suitably-sized string buffers, then parse what you got. One good function for parsing a string is sscanf() which is just like scanf() except it reads from a string instead.

This will be much easier, less annoying, and just generally better. Oh, and of course never use gets().

Something like this (untested):

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

int main(void)
{
  char line[256];

  if(fgets(line, sizeof line, stdin))
  {
    int count;
    if(sscanf(line, "%d", &count) == 1)
    {
      while(count > 0)
      {
        if(fgets(line, sizeof line, stdin))
        {
          printf("%s", line);
          --count;
        }
        else
          break;
      }
    }
  }
  return EXIT_SUCCESS;
}

edited May 23 '17 at 11:57

Community

1
1

answered Apr 17 '14 at 14:21

unwind

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I m a newbie can you please give a example how to use fgets() – tech_boy Apr 17 '14 at 14:22
Can you explain the flow i am not able to get the functionality of the methods mention – tech_boy Apr 17 '14 at 14:34
@tech_boy I made `fgets()` and `sscanf()` into links, so you can read the documentation to figure out exactly how those functions work. – unwind Apr 17 '14 at 14:36

score 0 · Answer 2 · answered Apr 17 '14 at 14:21

Dont use fflush(stdin). use getchar() to clear the [enter] character left after scanf() as,

#include <stdio.h>
#include<stdlib.h>
#include <string.h>
int main(void) {
    char a[1001];
    int t,i;
    scanf("%d",&t);
     getchar();
    while(t--)
    {

        gets(a);
        printf("%d\t",t);
        puts(a);

    }
    return 0;
}

it works.

how to take input of two string?

2 Answers2

Linked