Museum

Home

Lab Overview

Retrotechnology Articles

Online Manuals

⇒ pipe(2) — DG/UX R4.11MU05

Media Vault

Software Library

Restoration Projects

Artifacts Sought

Related Articles

sh(1)

fork(2)

read(2)

readv(2)

write(2)

writev(2)



pipe(2)                        DG/UX R4.11MU05                       pipe(2)


NAME
       pipe - create an interprocess channel

SYNOPSIS
       #include <unistd.h>

       int  pipe (fildes)
       int  fildes[2];

   where:
       fildes    Address of an array of two file descriptors

DESCRIPTION
       pipe 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 ONDELAY and ONONBLOCK flags are cleared.

       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.

       The FDCLOEXEC flag will be clear on both file descriptors.

       If the process exceeds its limit for open files, the call will fail.

       Pipes exist in the channel store, but not in the file name store or
       the flat file store.  Pipes have no file attributes except time-last-
       accessed, time-last-changed, time-last-modified, and size.

ACCESS CONTROL
       None.

RETURN VALUE
       0      The pipe was successfully created.

       -1     An error occurred.  errno is set to indicate the error.

DIAGNOSTICS
       Errno may be set to one of the following error codes:

       EFAULT    The fildes[] buffer is an invalid area of the process's
                 address space.

       EMFILE    Pipe will fail if NOFILE-1 or more file descriptors are
                 currently open.

       ENFILE    The system file table is full.

SEE ALSO
       sh(1), fork(2), read(2), readv(2), write(2), writev(2).


Licensed material--property of copyright holder(s)

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026