LDP
/
man-pages
mirror of https://github.com/mkerrisk/man-pages
0
1
Fork 0
Code Releases Activity

pipe.2: Add description of new pipe2() syscall 

pipe2() was added in 2.6.27.  Describe the O_NONBLOCK and
O_CLOEXEC flags.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Michael Kerrisk 2008-10-10 08:10:48 +02:00
parent a3bb543ceb
commit 14393ac023
1 changed files with 48 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
man2/pipe.2
View File

@ -31,14 +31,22 @@
.\" Modified 2005, mtk: added an example program
.\" Modified 2008-01-09, mtk: rewrote DESCRIPTION; minor additions
.\" to EXAMPLE text.
.\" 2008-10-10, mtk: add description of pipe2()
.\"
.TH PIPE 2 2008-01-09 "Linux" "Linux Programmer's Manual"
.TH PIPE 2 2008-10-10 "Linux" "Linux Programmer's Manual"
.SH NAME
pipe \- create pipe
pipe, pipe2 \- create pipe
.SH SYNOPSIS
.nf
.B #include <unistd.h>
.sp
.BI "int pipe(int " pipefd "[2]);"
.sp
.B #define _GNU_SOURCE
.B #include <unistd.h>
.sp
.BI "int pipe2(int " pipefd "[2], " flags );
.fi
.SH DESCRIPTION
.BR pipe ()
creates a pipe, a unidirectional data channel that
@ -54,6 +62,30 @@ Data written to the write end of the pipe is buffered by the kernel
until it is read from the read end of the pipe.
For further details, see
.BR pipe (7).
If
.IR flags
is 0, then
.BR pipe2 ()
is the same as
.BR pipe ().
The following values can be bitwise ORed in
.IR flags
to obtain different behavior:
.TP 12
.B O_NONBLOCK
Set the
.BR O_NONBLOCK
file status flag on the two new file descriptors.
Using this flag saves extra calls to
.BR fcntl ()
to achieve the same result.
.TP
.B O_CLOEXEC
Set the close-on-exec flag on the two new file descriptors.
See the description of the same flag in
.BR open (2)
for reasons why this may be useful.
.SH "RETURN VALUE"
On success, zero is returned.
On error, \-1 is returned, and
@ -65,13 +97,27 @@ is set appropriately.
.I pipefd
is not valid.
.TP
.B EINVAL
.RB ( pipe2 ())
Invalid value in
.IR flags .
.TP
.B EMFILE
Too many file descriptors are in use by the process.
.TP
.B ENFILE
The system limit on the total number of open files has been reached.
.SH VERSIONS
.BR pipe2 ()
was added to Linux in version 2.6.27;
glibc support is available starting with
version 2.9.
.SH "CONFORMING TO"
.BR pipe ():
POSIX.1-2001.
.BR pipe2 ()
is Linux-specific.
.SH EXAMPLE
.\" fork.2 refers to this example program.
The following program creates a pipe, and then