I've been researching this problem and I am pretty sure that the issue is related to the while loop and the piping. There are plenty of other threads about this issue that recommend removing the pipe and using redirection. However, I haven't been able to get it working using the ssh and grep command.
As you can see, the TOTAL is available within the while loop but is then empty after the loop exits.
Any suggestions appreciated.
Thanks for you help.
---------- Post updated at 02:01 PM ---------- Previous update was at 10:35 AM ----------
Hah! So why is it, you bash (no pun intended) your head against a wall for a couple of days, trying every possible combination you can think of. No sooner you post the question, the light bulb goes off.
So, I moved the ssh command to the for loop output to a file and then used redirection for the while loop. Its not perfect, but at least I have my variables now and can work on the other issues I have.
I've been wondering if I can make mutexes much easier to use in C++ with creative use of a locking class and variable scope, but I'm not sure if things happen in the order I want. Here's pseudocode for something that could use the class:
int someclass::getvalue()
{
int retval;
... (0 Replies)
Hi,
I am stuck while developing a shell sub-routine which checks the log file for "success" or "failure". The subroutine reads the log file and checks for key word "success", if found it set the variable (found=1). It returns success or failure based on this variable.
My problem is, I can... (2 Replies)
Hi All,
I am new to unix shell scripting,
in the below script "num" is an input file which contains a series of numbers example :
2
3
5
8
I want to add the above all numbers and want the result finally outside the while loop. it prints the value zero instead of the actual expected... (13 Replies)
Hi,
I want to know about the variable scope in shell script.
How can we use the script argument inside the function?
fn () {
echo $1 ## I want this argument should be the main script argument and not the funtion argument.
}
also are there any local,global types in shell script?
if... (3 Replies)
Hi,
I use Korn Shell. Searched Forum and modified the way the file is input to the while loop, but still the variable does not seem to be retaining the final count.
while read name
do
Tmp=`echo $name | awk '{print $9 }'`
Count=`cat $Tmp | wc -l`... (6 Replies)
Hello! Before you "bash" me with
- Not another post of this kind
Please read on and you will understand my problem...
I am using the below to extract a sum of the diskIO on a Solaris server.
#!/bin/sh
PATH=/usr/bin:/usr/sbin:/sbin; export PATH
TEMP1="/tmp/raw-sar-output.txt$$"... (3 Replies)
Hi All
Is there is any way to maintain the scope of the variable in unix
Example
x=1
j=1
while
do
..
....
....
while
do
..
..
x=x+1
done
#inner most while loop ends here
done
#outer loop ends here (8 Replies)
Hi,
I'm a Delphi developer new to linux, new to this forums and new to BASH programming and got a new task in my work: maintaining an existing set of BASH scripts. First thing I want to do is making the code more reliable as in my opinion it's really bad written. So here's the quest:
I'm... (6 Replies)
I have to admit that i have not used Perl at all and this is a singular occasion where i have to patch an existing Perl script. I dearly hope i do not have to do it again for the next 15 years and therefore try to avoid having to learn the programming language in earnest.
The OS is AIX 7.1, the... (2 Replies)
Cope sample1: test.sh
i=0
echo " Outside loop i = $i "
while
do
i=$(( $i + 1))
echo "Inside loop i = $i "
done
echo " Out of loop i is : $i "
When run output :
Outside loop i = 0
Inside loop i = 1
Inside loop i = 2
Inside loop i = 3
Inside loop i = 4
Inside loop i = 5
Inside... (8 Replies)
Discussion started by: Adarshreddy01
8 Replies
LEARN ABOUT DEBIAN
parallel-ssh
pssh(1) General Commands Manual pssh(1)NAME
pssh -- parallel ssh program
SYNOPSIS
pssh [-vAiIP] [-h hosts_file] [-H [user@]host[:port]] [-l user] [-p par] [-o outdir] [-e errdir] [-t timeout] [-O options] [-x args] [-X
arg] command ...
pssh -I [-vAiIP] [-h hosts_file] [-H [user@]host[:port]] [-l user] [-p par] [-o outdir] [-e errdir] [-t timeout] [-O options] [-x args] [-X
arg] [command ...]
DESCRIPTION
pssh is a program for executing ssh in parallel on a number of hosts. It provides features such as sending input to all of the processes,
passing a password to ssh, saving output to files, and timing out.
OPTIONS -h host_file
--hosts host_file
Read hosts from the given host_file. Lines in the host file are of the form [user@]host[:port] and can include blank lines and com-
ments (lines beginning with "#"). If multiple host files are given (the -h option is used more than once), then pssh behaves as
though these files were concatenated together. If a host is specified specified multiple times, then pssh will connect the given
number of times.
-H [user@]host[:port]
--host [user@]host[:port]
-H "[user@]host[:port] [ [user@]host[:port ] ... ]"
--host "[user@]host[:port] [ [user@]host[:port ] ... ]"
Add the given host strings to the list of hosts. This option may be given multiple times, and may be used in conjunction with the
-h option.
-l user
--user user
Use the given username as the default for any host entries that don't specifically specify a user.
-p parallelism
--par parallelism
Use the given number as the maximum number of concurrent connections.
-t timeout
--timeout timeout
Make connections time out after the given number of seconds. With a value of 0, pssh will not timeout any connections.
-o outdir
--outdir outdir
Save standard output to files in the given directory. Filenames are of the form [user@]host[:port][.num] where the user and port
are only included for hosts that explicitly specify them. The number is a counter that is incremented each time for hosts that are
specified more than once.
-e errdir
--errdir errdir
Save standard error to files in the given directory. Filenames are of the same form as with the -o option.
-x args
--extra-args args
Passes a extra SSH command-line arguments (see the ssh(1) man page for more information about SSH arguments). This option may be
specified multiple times. The arguments are processed to split on whitespace, protect text within quotes, and escape with back-
slashes. To pass arguments without such processing, use the -X option instead.
-X arg
--extra-arg arg
Passes a single SSH command-line argument (see the ssh(1) man page for more information about SSH arguments). Unlike the -x option,
no processing is performed on the argument, including word splitting. To pass multiple command-line arguments, use the option once
for each argument.
-O options
--options options
SSH options in the format used in the SSH configuration file (see the ssh_config(5) man page for more information). This option may
be specified multiple times.
-A
--askpass
Prompt for a password and pass it to ssh. The password may be used for either to unlock a key or for password authentication. The
password is transferred in a fairly secure manner (e.g., it will not show up in argument lists). However, be aware that a root user
on your system could potentially intercept the password.
-i
--inline
Display standard output and standard error as each host completes.
-v
--verbose
Include error messages from ssh with the -i and options.
-I
--send-input
Read input and send to each ssh process. Since ssh allows a command script to be sent on standard input, the -I option may be used
in lieu of the command argument.
-P
--print
Display output as it arrives. This option is of limited usefulness because output from different hosts are interleaved.
EXAMPLE
Connect to host1 and host2, and print "hello, world" from each:
pssh -i -H "host1 host2" echo "hello, world"
Print "hello, world" from each host specified in the file hosts.txt:
pssh -i -h hosts.txt echo "hello, world"
Run a command as root with a prompt for the root password:
pssh -i -h hosts.txt -A -l root echo hi
Run a long command without timing out:
pssh -i -h hosts.txt -t 0 sleep 10000
If the file hosts.txt has a large number of entries, say 100, then the parallelism option may also be set to 100 to ensure that the com-
mands are run concurrently:
pssh -i -h hosts.txt -p 100 -t 0 sleep 10000
Run a command without checking or saving host keys:
pssh -i -H host1 -H host2 -x "-O StrictHostKeyChecking=no -O UserKnownHostsFile=/dev/null -O GlobalKnownHostsFile=/dev/null" echo hi
EXIT STATUS VALUES
0 Success
1 Miscellaneous error
2 Syntax or usage error
3 At least one process was killed by a signal or timed out.
4 All processes completed, but at least one ssh process reported an error (exit status 255).
5 There were no ssh errors, but at least one remote command had a non-zero exit status.
AUTHORS
Written by Brent N. Chun <bnc@theether.org> and Andrew McNabb <amcnabb@mcnabbs.org>.
http://code.google.com/p/parallel-ssh/
SEE ALSO ssh(1), pscp(1), prsync(1), pslurp(1), pnuke(1)
February 25, 2010 pssh(1)