09-23-2008
10 More Discussions You Might Find Interesting
1. Filesystems, Disks and Memory
Hello!
How I can increase or decrease predefined pipe buffer size?
System FreeBSD 4.9 and RedHat Linux 9.0
Thanks! (1 Reply)
Discussion started by: Jus
1 Replies
2. Shell Programming and Scripting
Hi,
Can the cd command be invoked using pipes???
My actual question is slightly different. I am trying to run an executable from different folders and the path of these folders are obtained dynamically from the front end. Is there a way in which i can actually run the executable... (2 Replies)
Discussion started by: Sinbad
2 Replies
3. UNIX for Dummies Questions & Answers
im trying to figure out how to do the following:
using pipes to combine grep and find commands to print all lines in files that start with the letter f in the current directory that contain the word "test" for example?
again using pipes to combine grep and find command, how can I print all... (1 Reply)
Discussion started by: ez45
1 Replies
4. UNIX for Advanced & Expert Users
Hi all,
I tried the following command
$ find / -name xyx | ls -l
so logically it should show the listing of directory xyz , assuming there's only one instance of xyz . But the above command shows the listing of current directory instead.
I got the desired result using it in the... (4 Replies)
Discussion started by: bijeet_sunny
4 Replies
5. Programming
Hello all, I am trying to learn more about programming Unix pipes in C.
I have created a pipe that does od -bc < myfile | head
Now, I am trying to create od -bc < myfile | head | wc
Here is my code, and I know I might be off, thats why I am here so I can get some clarification.
#include... (1 Reply)
Discussion started by: petrca
1 Replies
6. Shell Programming and Scripting
Here is an example code that shows the issue I have:
#!/bin/bash
counter() {
seq 1000 | while read NUM; do
echo $NUM
echo "debug: $NUM" >&2
sleep 0.1 # slow it down so we know when this loop really ends
done
}
counter | grep --line-buffered "" | head -n1
... (10 Replies)
Discussion started by: tokland
10 Replies
7. Programming
problem solved. (1 Reply)
Discussion started by: superfons
1 Replies
8. Programming
I want to have a message send & receive through 2 half-duplex pipes
Flow of data
top half pipe
stdin--->parent(client) fd1--->pipe1-->child(server) fd1
bottom half pipe
child(server) fd2---->pipe2--->parent(client) fd2--->stdout
I need to have boundary structed message... (1 Reply)
Discussion started by: ouou
1 Replies
9. Programming
Hi!
I'm having problems with pipes... I need comunnications with childs processes and parents, but only one child can comunnicate with parent (first child), others childs can't.
A brief of code:
if(pipe(client1r)<0){
perror("pipe");
}
... (1 Reply)
Discussion started by: serpens11
1 Replies
10. Shell Programming and Scripting
I already manage to get the output that i want.. but wat if removing all the pipes and convert it 1 liner with less pipes. My command below can get the ouput that i want. i just want to remove the pipes or less pipes.
#cat file1
us-west-2a running i-3397a421... (2 Replies)
Discussion started by: kenshinhimura
2 Replies
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)