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 /*

 2  ============================================================================

 3  Name        : FileIO.c

 4  Author      : Cody

 5  Version     :

 6  Copyright   : Written By Cody

 7  Description :

 8  ============================================================================

 9  */

10 

11 #include <stdio.h>

12 #include <stdlib.h>

13 #include <string.h>

14 

15 

16 #include <sys/types.h>

17 #include <sys/stat.h>

18 #include <fcntl.h>

19 

20 #include <unistd.h>

21 

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

23 

24     int fromFd = open("/root/cody.txt",O_RDONLY);

25     if(fromFd == -1)

26     {

27         perror("打开From文件");

28         exit(0);

29     }

30 

31     int toFd = open("/root/to_cody.txt",O_WRONLY | O_CREAT);

32     if(toFd == -1)

33     {

34         perror("打开To文件");

35         exit(0);

36     }

37 

38     read_To_File(fromFd,toFd);

39 

40     close(fromFd);

41     close(toFd);

42 

43     return EXIT_SUCCESS;

44 }

45 

46 

47 /**

48  * 将一个文件的内容，写入到另一个文件

49  */

50 int read_To_File(int fromFd,int toFd)

51 {

52 

53     char buf[512];

54 

55     int readBytes;

56 

57     int writeBytes;

58 

59     if(fromFd == -1 || toFd == -1) return -1;

60 

61     memset(buf,0,sizeof(buf));

62     printf("开始读写\n");

63     while((readBytes = read(fromFd,buf,sizeof(buf))) > 0)

64     {

65         puts(buf);

66 

67         writeBytes = write(toFd,buf,readBytes);

68 

69         if(writeBytes == -1)

70         {

71             perror("write error");

72         }

73 

74         memset(buf,0,sizeof(buf));

75     }

76 

77     return 1;

78 }