系统编程之文件编程file_cp

来源：互联网发布：java判断文件类型编辑：程序博客网时间：2024/04/29 16:32

#include<string.h>

#include <strings.h>

#include <stdio.h>

#include <stdlib.h>

#define BUFFER_SIZE 1024

int main(int argc, char ** argv)

    FILE *from_fd;

    FILE *to_fd;

    long file_len=0;

    char buffer[BUFFER_SIZE];

   // char *ptr;

     /*判断入参*/

     if(argc!=3)

         printf("Usage:%s fromfile tofile\n",argv[0]);

         exit(1);

     /*打开源文件*/

     if((from_fd=fopen(argv[1],"rb"))==NULL)

         printf("Open %s Error\n",argv[1]);

         exit(1);

     /*创建目的文件

*  w      Truncate  file  to zero length or create text file for writing.

              The stream is positioned at the beginning of the file.

*/

     if((to_fd=fopen(argv[2],"wb"))==NULL)

         printf("Open %s Error\n",argv[2]);

         exit(1);

     /*测得文件大小*/

     fseek(from_fd,0L,SEEK_END);

     file_len=ftell(from_fd);

     fseek(from_fd,0L,SEEK_SET);

     printf("from fiel size id %d\n",file_len);

      /*进行文件拷贝*/

             while(!feof(from_fd))

                 fread(buffer,BUFFER_SIZE,1,from_fd);

                 if(BUFFER_SIZE >= file_len) //文件太小

                     fwrite(buffer,file_len,1,to_fd);

                 else                       //文件太大

                     fwrite(buffer,BUFFER_SIZE,1,to_fd);

                     file_len-=BUFFER_SIZE;

                 bzero(buffer,BUFFER_SIZE);

       fclose(from_fd);

       fclose(to_fd);

       exit(0);