我也来发个小加密程序此加密对回车不是支持的很好:(

#include <stdlib.h>
#include<stdio.h>
int jiami();
int jiemi();
int display();    
void main()
{
        int choice=1;
        while(choice!=4)
        {
            system("cls.exe");
            printf("\t\t请选择你要做的操作：\n");
            printf("\t\t\t1.加密文件\n");
            printf("\t\t\t2.解密文件\n");
            printf("\t\t\t3.显示文件\n");
            printf("\t\t\t4.退出\n");
            printf("\t\t请键入你的选择:");
            scanf("%d",&choice);
            if(choice==1)
                jiami();
            else if(choice==2)
                jiemi();
            else if(choice==3)
            {  display();
               getchar();
               getchar();
            }
        }

}

int jiami()
{
    FILE *fp;
    char filename[100],ch,ch1;
    int i=0,j=0;
    printf("请输入要加密的文件：");
    scanf("%s",filename) ;
    if((fp=fopen(filename,"r+"))==NULL)
    {
        printf("\nerror opening file");
        return 0;
    }
    while(!feof(fp))
    {
        ch=fgetc(fp);                                         
        j++;
        
    }
    rewind(fp);
    while(i<j-1)
    {
        ch=fgetc(fp);
        ch=ch+6;
        fseek(fp,i,0);
        fputc(ch,fp);                                            
        i++;
        fseek(fp,i,0);
    }
        //printf("%c",ch=fgetc(fp));
    fclose(fp);
}
int jiemi()
{
    FILE *fp;
    char filename[100],ch,ch1;
    int i=0,j=0;
    printf("请输入要解密的文件：");
    scanf("%s",filename) ;
    if((fp=fopen(filename,"r+"))==NULL)
    {
        printf("\nerror opening file");
        return 0;
    }
    while(!feof(fp))
    {
        ch=fgetc(fp);                                         
        j++;
        
    }
    rewind(fp);
    while(i<j-1)
    {
        ch=fgetc(fp);
        ch=ch-6;
        fseek(fp,i,0);
        fputc(ch,fp);                                            
        i++;
        fseek(fp,i,0);
    }
        //printf("%c",ch=fgetc(fp));
    fclose(fp);
}

int display()
{
    FILE *fp;
    char filename[100],ch,ch1;
    int i=0,j=0;
    printf("请输入要显示的文件：");
    scanf("%s",filename) ;
    if((fp=fopen(filename,"r+"))==NULL)
    {
        printf("\nerror opening file");
        return 0;
    }
    while(!feof(fp))
    {
        ch=fgetc(fp);                                         
        j++;
        
    }
    rewind(fp);
    while(!feof(fp))
    {
        putchar(fgetc(fp));
        
    }
        //printf("%c",ch=fgetc(fp));
    fclose(fp);
}
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