ponteiros e strchr o que faz

/* strchr example */
#include <stdio.h>
#include <string.h>
#include <cstdio>
#include <cstring>
using namespace std;

int main ()
{
    char s[100],c;

    printf("Introd. uma string: "); gets(s);
    printf("Introd. um char   : "); scanf(" %c", %c);

    puts(stchr(s,c));
  /*char str[] = "This is a sample string";
  char * pch;
  printf ("Looking for the 's' character in \"%s\"...\n",str);
  pch=strchr(str,'s');
  while (pch!=NULL)
  {
    printf ("found at %d\n",pch-str+1);
    pch=strchr(pch+1,'s');
  }*/
  return 0;
}