String reverse output, requires calling function to implement __ function

Simple, requires calling function implementation

#include <stdio.h>
#include <string.h>
void inv (char S1[],char s2[])
{
int l,i;
L = strlen (S1);
for (i = l-1;i >= 0;i--)
{
s2[l-i-1] = s1[i];
int main ()
{
int i;
Char s1[100] = {0},s2[100] = {0};
while (~SCANF ("%s", S1))
{
inv (S1,S2);
for (i = 0;i < strlen (S2); i++)
{
printf ("%c", S2[i]);
//for (i = strlen (S1) -1;i >= 0;i-) printf ("%c", s1[i);//puts (S2)
;        printf ("\ n");
Puts ("");
}
}

Here's a pit, here. Read the string do not use the gets function, will read out a space, scanf does not exist this problem.

In addition, to avoid the array output garbled, it is necessary to initialize the string array when defining it.