Question

i have a piece of code in C .But i am not able to understand its output

#include<stdio.h>
main()
{

char a1[20];
char a2[30];
char a3[40];
scanf("%s",&a1);
gets(a2);
fgets(a3,sizeof(a3),stdin);
printf("%d,%d,%d\n",strlen(a1),strlen(a2),strlen(a3));
 }   

When i enter my input like

 amit
 singh

output comes out to be 4,0,6 and fgets doest not allow me to enter any string ,i am able to enter only 2 inputs?

Answer 1

1. input is "amit\nsingh\n"
2. the scanf consumes “amit” (and writes that into a1)
3. the gets consumes “\n” (and writes empty string to a2)
4. the fgets consumes “singh\n” (which it writes to a3)

The output is correct.

Do not EVER use gets!

1. http://pubs.opengroup.org/onlinepubs/9699919799/functions/fscanf.html
2. http://pubs.opengroup.org/onlinepubs/9699919799/functions/gets.html
3. http://pubs.opengroup.org/onlinepubs/9699919799/functions/fgets.html