actually, it has no -p option. it has a p type, like
Code:
mknod fifo-file p
where can you use it in real time? any UNIX system.
What are they used for? Bridging together programs which are difficult to use anonymous pipes with. To get an anonymous pipe you have to be a child process of whatever created it, but named pipes can be opened by any arbitrary process, child or not.
They're also used to make dynamic things which act like files, so when something tries to read what used to be a config file or somesuch they get dynamically-generated output from a program.
Can someone please tell me what the command mknod does and what it's syntax is? I can't find it in my "Unix for dummies" book or "Unix in s nutshell". I found it in an existing script that I want to copy, but I want to understand what I am doing. The script is going to do a full export of an... (3 Replies)
from the man page of su:
EXAMPLES
Example 1: Becoming User bin While Retaining Your Previously
Exported Environment
To become user bin while retaining your previously exported
environment, execute:
example% su bin
Example 2: Becoming User bin and ... (4 Replies)
I'm trying to use the "mknod" call in C to create a clone of /dev/null. I am stumped as to the final parameter I should provide to "mknod()". I am supposed to give it a type dev_t, which specifies a major & minor number. I want to specify major 3, minor 1, but how can I do this?
dev_t seems to... (2 Replies)
Hello,
I'm trying to help a guy out on a VMWARE server, running what looks like a cut down version of redhat? 2.4.9-vmnix2 ...
Bascially the box serves vm clients via allocating a LUN from a SAN.. to cut a long story short, I need to find out which SAN the luns are comming from (could be 1... (0 Replies)
Hi,
I'm a oracle DBA with little knowledge of Unix.
I wanted to write some shell scripts which will be helpful for DBA's regular activity.
As i'm a new to oracle with unix can any plese tell me what are all the activities can be done throgh Unix Shell Scripts also suggest me how to learn... (1 Reply)
this is existing issue for this nfs client, which mounts windows exported
file system, and this is only one UNIX box has this problem, other boxes are
fine.
Here is from messages file.
Jan 24 03:11:10 venus nfs: NFS mknod failed for
server arc: error 2 (RPC: Can't decode result)
Jan... (0 Replies)
Hiya all ... i am a newbie to UNIX,
Just want to knwo what this command does:
/sbin/ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'
I think, 'grep shows the line with 'inet addr' (which is the 2nd line, displaying the IP Address, Broadcast Address and Subnet Mask) ... Is... (8 Replies)
I have this working ksh, and it returns like below:
LOGICAL VOLUME: prod_2048_005 VOLUME GROUP: prod1vg
TYPE: raw WRITE VERIFY: off
PHYSICAL VOLUME: hdisk108 VOLUME GROUP: prod1vg
TOTAL PPs: 1023 (130944 megabytes) VG DESCRIPTORS: 1
USED PPs: 904 (115712 megabytes) MAX REQUEST: 1 megabyte... (1 Reply)
Hi Guys,
On my AIX server , I have this file "mknod" present in the /etc/ directory. When i try opening it , I dont find
any ascii characters. It shows some encryption/binary format which is not readable. Is it any executable ? what is the
purpose of having this file in etc folder? what if... (2 Replies)
Discussion started by: DBTuner
2 Replies
LEARN ABOUT HPUX
pipe
pipe(2) System Calls Manual pipe(2)NAME
pipe() - create an interprocess channel
SYNOPSIS DESCRIPTION
creates an I/O mechanism called a pipe and returns two file descriptors, fildes[0] and fildes[1]. fildes[0] is opened for reading and
fildes[1] is opened for writing.
A read-only file descriptor fildes[0] accesses the data written to fildes[1] on a first-in-first-out (FIFO) basis. For details of the I/O
behavior of pipes see read(2) and write(2).
By default, HP-UX pipes are not STREAMS-based. It is possible to generate the kernel so that all pipes created on a system are STREAMS-
based. This can only be done for HP-UX releases 10.0 and later. STREAMS-based FIFOs (created by or are not supported on HP-UX.
To generate a kernel that supports STREAMS-based pipes:
o STREAMS/UX must be installed.
o The module and the driver must be included in the file. (When STREAMS/UX is installed, and are automatically added to the system
file.)
o The tunable parameter (see streampipes(5)) must be set to 1 in the file. (This is not automatically done when STREAMS/UX is
installed.)
o The kernel must be generated and the system rebooted. Once this is done, all pipes created by will be STREAMS-based.
For more information, see
EXAMPLES
The following example uses to implement the command string
RETURN VALUE
returns one of the following values:
Successful completion.
Failure.
is set to indicate the error.
ERRORS
sets to one of the following error values if the corresponding condition is true.
or more file descriptors are currently open.
The system file table is full.
The file system lacks sufficient space to create the pipe.
Could not allocate resources for both Stream heads
(STREAMS-based pipes only).
SEE ALSO sh(1), read(2), write(2), popen(3S), privileges(5), streampipes(5), streamio(7).
STANDARDS CONFORMANCE pipe(2)