将任意两个指定的文件完成拷贝功能：比如：a.out a.txt b.txt 把a.txt的内容拷贝到b.txt 中

#include <stdio.h>

int main(int argc, char *argv[])
{
        if(argc!=3)
        {
            printf("Usage %s [file]\n",argv[0]);
            return -1;
        }

        FILE * fp1 = fopen(argv[1], "r");
        if(NULL==fp1)
        {
              perror("fp1 error");
              return -1;
        }
        FILE * fp2 = fopen(argv[2], "w");
        if(NULL==fp2)
        {
              perror("fp2 error");
              return -1;
        }
        int c;        
        if(fp1 && fp2)
        {
            while((c= fgetc(fp1))!= EOF)
            fputc(c, fp2);
        }

   
       fclose(fp1);
       fclose(fp2);
        
       return 0;
}