pipe(2) [opensolaris man page]

pipe(2) 							   System Calls 							   pipe(2)

NAME

       pipe - create an interprocess channel

SYNOPSIS

       #include <unistd.h>

       int pipe(int fildes[2]);

DESCRIPTION

       The  pipe() function creates an I/O mechanism called a pipe and returns two file descriptors, fildes[0] and fildes[1]. The files associated
       with fildes[0] and fildes[1] are streams and are both opened for reading and writing.  The O_NDELAY, O_NONBLOCK, and FD_CLOEXEC	flags  are
       cleared on both file descriptors. The fcntl(2) function can be used to set these flags.

       A  read	from  fildes[0] accesses the data written to fildes[1] on a first-in-first-out (FIFO) basis and a read from fildes[1] accesses the
       data written to fildes[0] also on a FIFO basis.

       Upon successful completion pipe() marks for update the st_atime, st_ctime, and st_mtime fields of the pipe.

RETURN VALUES

       Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

       The pipe() function will fail if:

       EMFILE	 More than {OPEN_MAX} file descriptors are already in use by this process.

       ENFILE	 The number of simultaneously open files in the system would exceed a system-imposed limit.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe 	   |
       +-----------------------------+-----------------------------+

SEE ALSO

       sh(1), fcntl(2), fstat(2), getmsg(2), poll(2), putmsg(2), read(2), write(2), attributes(5), standards(5), streamio(7I)

NOTES

       Since a pipe is bi-directional, there are two separate flows of data. Therefore, the size (st_size) returned by a  call	to  fstat(2)  with
       argument   fildes[0]  or  fildes[1]  is the number of bytes available for reading from fildes[0] or fildes[1] respectively. Previously, the
       size (st_size) returned by a call to fstat() with argument fildes[1] (the write-end) was the number of bytes  available	for  reading  from
       fildes[0] (the read-end).

SunOS 5.11							    23 Apr 2002 							   pipe(2)

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

NAME

       dup2 - duplicate an open file descriptor

SYNOPSIS

       #include <unistd.h>

       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 refer-
       ring 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).

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() 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(RLIMIT_NOFILE, ...).

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

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

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE 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							    19 Dec 2003 							  dup2(3C)

Linux and UNIX Man Pages

pipe(2) [opensolaris man page]

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