Linux C 中 open close read write 使用实例

这里实现的是将文件cody.txt中的内容拷贝到to_cody.txt中去。

 1 /*
  ============================================================================
  Name        : FileIO.c
  Author      : Cody
  Version     :
  Copyright   : Written By Cody
  Description :
  ============================================================================
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>

 #include <unistd.h>

 int main(int argc,char *argv[]) {

     int fromFd = open("/root/cody.txt",O_RDONLY);
     if(fromFd == -)
     {
         perror("打开From文件");
         exit();
     }

     int toFd = open("/root/to_cody.txt",O_WRONLY | O_CREAT);
     if(toFd == -)
     {
         perror("打开To文件");
         exit();
     }

     read_To_File(fromFd,toFd);

     close(fromFd);
     close(toFd);

     return EXIT_SUCCESS;
 }

 /**
  * 将一个文件的内容，写入到另一个文件
  */
 int read_To_File(int fromFd,int toFd)
 {

     char buf[];

     int readBytes;

     int writeBytes;

     if(fromFd == - || toFd == -) return -;

     memset(buf,,sizeof(buf));
     printf("开始读写\n");
     while((readBytes = read(fromFd,buf,sizeof(buf))) > )
     {
         puts(buf);

         writeBytes = write(toFd,buf,readBytes);

         if(writeBytes == -)
         {
             perror("write error");
         }

         memset(buf,,sizeof(buf));
     }

     return ;
 }