修改单词首字母大小写

/*
1 编写一个业务函数，实现字符串（前后各有三个空格，单词前后也均有空格）
" i am student, you are teacher " ，
各个单词首字符大写，结果如下" I Am Student, You Are Teacher " ，
要求1：实现所有接口 70
要求2：写出测试程序 30
*/

#include "stdlib.h"
#include "stdio.h"
#include "string.h"

int GetString(const char *str1 /*in*/, char *str2 /*in*/);

int GetString_Adv(const char *str1/*in*/, char **str2 /*out*/);
int GetString_Adv_Free1(char *str2);
int GetString_Adv_Free2(char **str2);

int GetString(const char *str1 /*in*/, char *str2 /*in*/)
{
char *p1 = NULL, *p2 = NULL;
int len = 0, i = 0;

if (str1 == NULL || str2 == NULL)
{
return -1;
}
len = strlen(str1);
strcpy(str2, str1);
if (len <1 )
{
return -1;
}
p1 = str2 +1;
p2 = str2;
for (i=0; i<len; i++)
{
if (isalpha(*p1) && isspace(*p2))
{
*p1 = *p1 - 32 ;
}
p1++;
p2++;
}
return 0;
}

void main11()
{
int ret = 0;
char *p = " i am student, you are teacher ";
char str2[1024*10] = {0};
//char *str3 = (char *)malloc(1024*10*sizeof(char ));
ret = GetString(p /*in*/,str2 /*in*/);
if (ret != 0)
{
return;
}
printf("%s ", str2);

system("pause");
}
int GetString_Adv(const char *str1/*in*/, char **pp2 /*out*/)
{
char *p1 = NULL, *p2 = NULL;
int len = 0, i = 0;
char *tmp = NULL;

if (str1 == NULL || pp2 == NULL)
{
return -1;
}
len = strlen(str1);

tmp = (char *)malloc((len+1) *sizeof(char));
if (tmp == NULL)
{
return -2;
}
strcpy(tmp, str1);

if (len <1 )
{
return -1;
}
//准备循环条件
p1 = tmp +1;
p2 = tmp;
for (i=0; i<len; i++)
{
if (isalpha(*p1) && isspace(*p2))
{
*p1 = *p1 - 32 ;
}
//准备循环条件
p1++;
p2++;
}
//赋值
*pp2 = tmp;
return 0;

}
//直接释放形参执向的内存空间，没有修改实参的值，不能有效的避免野指针
int GetString_Adv_Free1(char *str2)
{
if (str2 != NULL)
{
free(str2);
}
}

//直接释放形参执向的内存空间，间接去修改实参的值，有效的避免野指针
int GetString_Adv_Free2(char **str2)
{
char *tmp = *str2;
if (str2 == NULL)
{
return 0;
}
if (tmp != NULL)
{
free(tmp);
*str2 = NULL;
}
}

void main()
{
int ret = 0;
char *p = " i am student, you are teacher ";
//char str2[1024*10] = {0};
//str2 = 0x11;
//char *str3 = (char *)malloc(1024*10*sizeof(char ));
char *str2 = NULL;
ret = GetString_Adv(p /*in*/,&str2 /*out*/);
if (ret != 0)
{
return;
}
printf("%s ", str2);

if (str2 != NULL)
{
free(str2);
str2 = NULL;
}

GetString_Adv_Free1(str2);
system("pause");
}