Standard C Library Functions                             dup2(3C)



NAME
     dup2 - duplicate an open file descriptor

SYNOPSIS
     #include 

     int dup2(int fildes, int fildes2);


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,
     FDUP2FD, fildes2).

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

ERORS
     The dup2() function 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  current  resource  limit  returned  by
               getrlimit(RLIMITNOFILE, ...).


     EINTR     A signal was caught during the dup2() call.


     EMFILE    The  process  has  too  many  open   files.    See
               fcntl(2).


ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:




SunOS 5.11          Last change: 19 Dec 2003                    1






Standard C Library Functions                             dup2(3C)



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Standard                    
    
     MT-Level                     Async-Signal-Safe           
    


SEE ALSO
     close(2),   creat(2),   exec(2),   fcntl(2),   getrlimit(2),
     open(2), pipe(2), attributes(5), standards(5)











































SunOS 5.11          Last change: 19 Dec 2003                    2