大小写字符转换.cpp

我一开始学习C语言时写的很小的程序

// 大小写字符转换.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "stdio.h"
#include "string.h"
#include "io.h" 
#include "stdlib.h"
#include "malloc.h"



int main(void)
{   
	FILE *fs = NULL ;
	FILE *fp = NULL ; 
	char filename[128] ;
	char ch ;
  
	
	
	printf("\n");
	printf("                                大小写字符转换                                \n");
	printf("   /////////////////////////////////////////////////////////////////////////  \n");
	printf("  // The Function Of This SoftWare Is Convert Lowercase To Capital letter  // \n");
	printf(" ///                 Built on Wednesday, January 03, 2008                  ///\n");
	printf("  //                   CopyRight Reserved By INVENTEC                      // \n");
	printf("   /////////////////////////////////////////////////////////////////////////  \n");
	printf("\n\n");
	printf("Notes! Donot Use The File Name That Had Been Used!                          \n\n");
	printf("Please Input New File Name What You Want To Creat And Use.                  \n\n");
	printf("TIPS: Press '?' For Help.                                                   \n\n");
	
  
    a:
	printf("Inputs File Name:");
	gets(filename);
	if (filename[0] == '?')
	{
        printf("                               帮助信息                                 \n\n");
		printf("1.请确认您的文件名还未创建，如已创建，请重新输入新文件名。              \n\n");
		printf("2.请保证您的文件名大小不超过128个字。                                   \n\n");
		printf("3.此软件只保证英文小写字母对大写字母的转换，其它字符不在范围之内。      \n\n");
		printf("4.请按照提示输入。                                                      \n\n");
		printf("5.版权所有。                                                          \n\n\n");
		printf("Example:                                                  ←为回车符      \n");
		printf("Inputs File Name:test.txt  ←                                             \n");
		printf("Error!The File Name Existed! Please Try It again!                         \n");
		printf("Inputs File Name:testagain.txt  ←                                        \n");
		printf("Inputs The Letters And Finish By '#':Inventec Company#  ←                \n");
        printf("Outputs The Letters:INVENTEC COMPANY                                    \n\n");
		printf("The Leters You Input Had Been Written In This File.                       \n");
		printf("You Can Input: type [filename]  ←                                      \n\n");
		printf("D:\\当前目录\\type testagain.txt  ←                                      \n");
		printf("D:\\当前目录\\Inventec Company                                        \n\n\n");
        goto a;
	
	}
      
    if (strlen(filename) == 0)
    {
		goto a;
	}
  
    

	if ((strlen(filename) > 128))
	{
		printf("Error!The File Name OverRun! Please Try It again!                         \n");
		memset(filename,0,128);
		goto a;
		
	}
	else if (access(filename, 0) == 0)
	{
        printf("\nError!The File Name Existed! Please Try It again!                       \n\n");
		memset(filename,0,128);
	    goto a;
	
	}
    

    fs = fopen(filename,"w+");

	if(fs == NULL)
	{
		printf("cannot open file %s.\n",filename);
	    fclose(fs);
	    goto a;
	 }
	else
	{
        printf("\nInputs The Letters AND Finish By '#':                                     \n");
        
		ch = getchar();
		while (ch != '#')
		{
			fputc(ch,fs);
			ch = getchar();	
		}
   

		rewind(fs);
        printf("\nOutputs The Letters:                                                      \n");
		
		ch = fgetc(fs);
		while ( !feof(fs) )
		{   

			if ((ch < 123) && (ch > 96))
            {
				ch -= 32;
            }
			putchar(ch);
            ch = fgetc(fs);
		}
		
		fclose(fs);
	    printf("\n\n");
        printf("The Leters You Input Had Been Written In The File.                        \n\n");
	    printf("You Can Input: type [filename]                                            \n\n");
	}
    
    
		return 0;
}