查找字符串中指定字符的个数

#include<stdio.h>
#include<conio.h>
#define M 81
int fun(char *ss,char c)
{
  int i=0;
  for(;*ss!='\0';ss++)
    if(*ss==c)i++;
    return i;}
main()
{
  char a[M],ch;
  printf("\nplease enter a string:");
  gets(a);
  printf("\nplease enter a char:");
  ch=getchar();
  printf("\nThe number of the char is:%d\n",fun(a,ch));
}