从指定字符串删除指定字符

#include <stdio.h>
#include <stddef.h>
/*
* 从字符串str中删除指定的字符ch
*/
char* delete_special_char(char *str, char ch)
{
char *temp, *ptr;
if (str == NULL)
return NULL;
for(ptr = str,temp = str; (*ptr) != '\0';ptr++)
{
if( (*ptr) != ch)
*temp++ = *ptr;
}
*temp = '\0';
return str;
}
int main()
{
char s[1000] = "The writer would like to thank you!";
char del_ch = 'y';
char *ret_str;
     ret_str = delete_special_char(s,del_ch);

    puts(ret_str);

    return 0;
}