程序代码：

#include<stdio.h>
FILE*FileOpen(char *filename,char*mode)   /*打开文件的函数*/
{
    FILE*fp;
    fp=fopen(filename,mode);
    if(fp==NULL)
        printf("open file failed");
    else
        return (fp);
}
void FileCopy(FILE*file_in,FILE*file_out)  /*复制文件内容的函数*/
{
    char c;
    while((c=fgetc(file_in))!=EOF)
        fputc(c,file_out);
}
int main()
{
    FILE *fp1,*fp2;
    char s[20],c;
    printf("please input the file name:");
    gets(s);
    fp1=FileOpen(s,"r");
    fp2=FileOpen("fp2","w");
    FileCopy(fp1,fp2);
    while((c=fgetc(fp1)!=EOF))    /*将文件中小写想字母转换成大写后输出*/
    {
        if(c>='a'&&c<='z')
            printf("%c",c-32);
        printf("%c",c);
    }
    fclose(fp1);
    fclose(fp2);
    return 0;
}


运行情况：
please input the file name:File1
open file failedPress any key to continue
还弹出一个窗口：03.exe遇到问题需要关闭。