개요

• 솔라나라에 설명된 어플리케이션에 대해 맨 페이지를 찾아 출력한다.
• MAN 페이지에 대한 설명은 윈디하나의 솔라나라: MAN 페이지을 참고하자.
• svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.

dup3(3c)

dup2(3C)                 Standard C Library Functions                 dup2(3C)

NAME
       dup2, dup3 - duplicate an open file descriptor

SYNOPSIS
       #include <unistd.h>

       int dup2(int fildes, int fildes2);

       int dup3(int fildes, int fildes2, int flags);

DESCRIPTION
       The  dup2() function causes the file descriptor fildes2 to refer to the
       same file as fildes. The fildes argument is a file descriptor referring
       to an open file, and fildes2 is a non-negative integer  less  than  the
       current  value  for the maximum number of open file descriptors allowed
       the calling process. See getrlimit(2). If fildes2 already refers to  an
       open file, not fildes, it is closed first. If fildes2 refers to fildes,
       or  if  fildes is not a valid open file descriptor, fildes2 will not be
       closed first.


       The dup2() function is equivalent to fcntl(fildes, F_DUP2FD, fildes2).


       The dup3() function causes the file descriptor fildes2 to refer to  the
       same file as fildes. The fildes argument is a file descriptor referring
       to  an  open  file, and fildes2 is a non-negative integer less than the
       current value for the maximum number of open file  descriptors  allowed
       the  calling process. See getrlimit(2). If fildes2 already refers to an
       open file, not fildes, it is closed first. If fildes2 refers to fildes,
       an error is returned. The flags argument can include  O_CLOEXEC  and/or
       O_CLOFORK;  these  flags  respectively set FD_CLOEXEC and FD_CLOFORK on
       the new file descriptor. If these flags are not set in the flags  argu‐
       ment,  the corresponding flags will be cleared on the new file descrip‐
       tor.


       The dup3() function is equivalent to fcntl(fildes,  F_DUP3FD,  fildes2,
       fd_flags),  where  fd_flags  is  a  mapping  of  O_CLOEXEC/O_CLOFORK to
       FD_CLOEXEC/FD_CLOFORK.

RETURN VALUES
       Upon successful completion a non-negative integer representing the file
       descriptor is returned. Otherwise, −1 is returned and errno is  set  to
       indicate the error.

ERRORS
       The dup2() and dup3() functions will fail if:

       EBADF     The fildes argument is not a valid open file descriptor.


       EBADF     The fildes2 argument is negative or is not less than the cur‐
                 rent  resource  limit  returned  by  getrlimit(RLIMIT_NOFILE,
                 ...).


       EINTR     A signal was caught during the function call.


       EINVAL    The fildes argument  is  the  same  file  descriptor  as  the
                 fildes2 argument, or flags has bits set other than FD_CLOEXEC
                 or FD_CLOFORK.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:

       tab()  box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE TYPEAT‐
       TRIBUTE VALUE _ Interface  StabilityCommitted  _  MT-LevelAsync-Signal-
       Safe _ StandardSee standards(7).


SEE ALSO
       close(2),  creat(2), exec(2), fcntl(2), getrlimit(2), open(2), pipe(2),
       attributes(7), standards(7)

HISTORY
       The dup3() function was added to Oracle Solaris in Solaris 11.4.0.


       The dup2() function has been included in all Sun and Oracle releases of
       Solaris.

Oracle Solaris 11.4               27 Aug 2025                         dup2(3C)