03-17-2009
7 More Discussions You Might Find Interesting
1. Filesystems, Disks and Memory
First time so excuse my ignorance please.
I may not be accurately describing the issue.
I have inherited a small lab mostly SUN V120s.
We lost power and are trying to recover.
Nope no backups...
The primary issue I have is 1 box is an Oracle Server.
It has 2 36Gb harddrives.
I am able to... (3 Replies)
Discussion started by: murphsr
3 Replies
2. UNIX for Dummies Questions & Answers
I am really stuck on something I am sure you all will find simple.
I am VERY new to shell scripting and I am trying to figure out how to do a or statement below. So if it = 11 or 31 then...
if ; then
Please keep in mind I do not know much on shell scripting and thank you in advance as... (8 Replies)
Discussion started by: LRoberts
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3. Shell Programming and Scripting
Hi,
I want to do SSH on many different machines and then run some commands on them. A binary application randomly generates IP addresses and my script will take care of doing SSH.
$ ./IPGen.exe | ./myScript.sh
my script looks like this:
while read line; do
result1=$(ssh $line... (2 Replies)
Discussion started by: siavash
2 Replies
4. Homework & Coursework Questions
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
Hey whats up everyone,
Currently I'm stuck. In this question I have to use the following commands test, shift,... (7 Replies)
Discussion started by: AdamSahp
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5. Homework & Coursework Questions
Good evening, I'm trying to do my own shell and I encountered some issues while creating it. Indeed when I try such a command I have
DAUPHINE> DAUPHINE> ls -l | grep terminal > fichier
DAUPHINE> cat fichier
My shell is named DAUPHINE
Whereas I should have:
Code:
... (0 Replies)
Discussion started by: AntoineCompagni
0 Replies
6. Post Here to Contact Site Administrators and Moderators
https://www.unix.com/shell-programming-and-scripting/264504-filter-blocks-awk.html
Can't see it anymore ..
Thanks ! (0 Replies)
Discussion started by: greycells
0 Replies
7. Shell Programming and Scripting
Hi,
i want use this Comand for my psql request
sh ssh -o StrictHostKeyChecking=no rootatemailaddress.de sudo psql -U postgres -c "select pg_terminate_backend(pid) from pg_stat_activity where datnam=\'$DB\';"'"
but the shell lost the inverted comma for datnam=\'$DB\'. The request deliver... (2 Replies)
Discussion started by: peterpane007
2 Replies
PIPE(2) System Calls Manual PIPE(2)
NAME
pipe - create an interprocess channel
SYNOPSIS
pipe(fildes)
int fildes[2];
DESCRIPTION
The pipe system call creates an I/O mechanism called a pipe. The file descriptors returned can be used in read and write operations. When
the pipe is written using the descriptor fildes[1] up to 4096 bytes of data are buffered before the writing process is suspended. A read
using the descriptor fildes[0] will pick up the data. Writes with a count of 4096 bytes or less are atomic; no other process can inter-
sperse data.
It is assumed that after the pipe has been set up, two (or more) cooperating processes (created by subsequent fork calls) will pass data
through the pipe with read and write calls.
The Shell has a syntax to set up a linear array of processes connected by pipes.
Read calls on an empty pipe (no buffered data) with only one end (all write file descriptors closed) returns an end-of-file.
SEE ALSO
sh(1), read(2), write(2), fork(2)
DIAGNOSTICS
The function value zero is returned if the pipe was created; -1 if too many files are already open. A signal is generated if a write on a
pipe with only one end is attempted.
BUGS
Should more than 4096 bytes be necessary in any pipe among a loop of processes, deadlock will occur.
ASSEMBLER
(pipe = 42.)
sys pipe
(read file descriptor in r0)
(write file descriptor in r1)
PIPE(2)