FilesExpand file tree

master

/

dup2.c

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

executable file

·

31 lines (28 loc) · 705 Bytes

master

/

dup2.c

Copy path

Top

File metadata and controls

• Code
• Blame

executable file

·

31 lines (28 loc) · 705 Bytes

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

/*

* Public domain dup2() lookalike

* by Curtis Jackson @ AT&T Technologies, Burlington, NC

* electronic address: burl!rcj

*

* dup2 performs the following functions:

*

* Check to make sure that fd1 is a valid open file descriptor.

* Check to see if fd2 is already open; if so, close it.

* Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd.

* Return fd2 if all went well; return BADEXIT otherwise.

*/

#include <fcntl.h>

#include <unistd.h>

#define BADEXIT -1

int

dup2(int fd1, int fd2)

{

if (fd1 != fd2) {

if (fcntl(fd1, F_GETFL) < 0)

return BADEXIT;

if (fcntl(fd2, F_GETFL) >= 0)

close(fd2);

if (fcntl(fd1, F_DUPFD, fd2) < 0)

return BADEXIT;

}

return fd2;

}