Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Grabbing value from command output and monitoring for changes
Top Forums Shell Programming and Scripting Grabbing value from command output and monitoring for changes Post 302447634 by alister on Monday 23rd of August 2010 10:59:20 PM
Old 08-23-2010
Quote:
Originally Posted by agama
Try something like this:

Code:
last_value=x
log_file=/tmp/log.file
while true
do
   your-command-string | read new_value
   if [[ $last_value != $new_value ]]
   then
       echo "$(date) $new_value" >>$log_file
       last_value=$new_value
   fi
   sleep 300      # every 5 minutes
done

This assumes bash -- most modern UNIXes link /usr/bin/sh to bash -- the [[ expression on the if are much more efficient. If AIX doesn't link to bash, and/or ksh isn't available, you'll have to use if [...].
Quote:
Originally Posted by agama
Code:
echo "psc -i 10050 -s RELOAD_SERVICE" | tmadmin | grep -vE 'Name|------' | tail -1| read new_value;

If there is more output following the value you want, but it is always line seven, then try this:
Code:
echo "psc -i 10050 -s RELOAD_SERVICE" | tmadmin | grep -vE 'Name|------' | awk 'NR==7 {print}' | read new_value;

Have a go with one of these and see if that works.
Those suggestions will often fail, since some very popular shells (bash included) will run the read command at the end of the pipeline in a subshell. The value assigned to new_value will never be visible in the script's environment, since it will only ever exist in the subshell's environment (which is destroyed as soon as the read is completed).

Example using bash:
Code:
$ x=; echo hello | read x; echo $x

$ x=; echo hello | ( read x; echo SUBSHELL: $x ); echo CURRENT: $x
SUBSHELL: hello
CURRENT:

Regards,
Alister
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Grabbing result of sql command

Hi guys, Is there a way a script can run an SQL statement and dump the results into a variable which can then be used later in the script? Thanks. (3 Replies)
Discussion started by: hern14
3 Replies

2. UNIX for Dummies Questions & Answers

Grabbing a value from an output file

I am executing a stored proc and sending the results in a log file. I then want to grab one result from the output parameters (bolded below, 2) so that I can store it in a variable which will then be called in another script. There are more details that get printed in the beginning of the log file,... (3 Replies)
Discussion started by: hern14
3 Replies

3. UNIX for Dummies Questions & Answers

File Missing When Grabbing Files from SFTP Server using SCP Command

Hi, I have this problem where sometimes my files would go missing when I schedule my crontab to run the SCP command to get file from the SFTP server. My crontab will run the scripts at an interval of 3 minutes (between the two scripts) The following is the setting in my crontab. ... (1 Reply)
Discussion started by: gingervitus
1 Replies

4. UNIX for Dummies Questions & Answers

Command display output on console and simultaneously save the command and its output

Hi folks, Please advise which command/command line shall I run; 1) to display the command and its output on console 2) simultaneous to save the command and its output on a file I tried tee command as follows; $ ps aux | grep mysql | tee /path/to/output.txt It displayed the... (7 Replies)
Discussion started by: satimis
7 Replies

5. Solaris

Monitoring the output of 'top' command on hourly basis.

I need to capture the following data on an hourly basis through cronjob scheduling:- 1. load averages 2. Total no. of processes. 3. CPU state 4. Memory 5. Top 3 process details. All the above information is available through the command 'top'. But here we need to automate the same and... (4 Replies)
Discussion started by: subharai
4 Replies

6. Infrastructure Monitoring

AIX monitoring tools for graphical output

Hi , I am new for Aix i am using IBM AIX server in our org. I am using tomcat and JDK 1.6 for our own ERP software the data base was stored in another server (windows ) i want to monitor my AIX server with graphical output from another system it is possible please help me, any other... (7 Replies)
Discussion started by: krishna_vnr`
7 Replies

7. Shell Programming and Scripting

script to mail monitoring output if required or redirect output to log file

Below script perfectly works, giving below mail output. BUT, I want to make the script mail only if there are any D-Defined/T-Transition/B-Broken State WPARs and also to copy the output generated during monitoring to a temporary log file, which gets cleaned up every week. Need suggestions. ... (4 Replies)
Discussion started by: aix_admin_007
4 Replies

8. Shell Programming and Scripting

Grabbing IP and zonename from multiline 'ifconfig' output

Hi There, I have a Solaris server that has a bunch of zones configured and I am trying to write a script that will take all interfaces other than the loopback ones (e.g. lo0:3 etc) and present them so that I can easily determine the zone that owns the IP So in the case of the following... (2 Replies)
Discussion started by: hcclnoodles
2 Replies

9. Shell Programming and Scripting

Grabbing value from file and run command in ``

Hi ALL, How can I make a script take data from a file and execute the commands within `` in the file n put that that in a variable? for i in `cat file` do file=`grep -i key file` cp ${file} test done file /tmp/`date +y`log /tmp/unix`date +y`log (1 Reply)
Discussion started by: 3junior
1 Replies

10. Shell Programming and Scripting

Insert title as output of command to appended file if no output from command

I am using UNIX to create a script on our system. I have setup my commands to append their output to an outage file. However, some of the commands return no output and so I would like something to take their place. What I need The following command is placed at the prompt: TICLI... (4 Replies)
Discussion started by: jbrass
4 Replies

LEARN ABOUT LINUX

shtool-echo

SHTOOL-ECHO.TMP(1)					      GNU Portable Shell Tool						SHTOOL-ECHO.TMP(1)

NAME

       shtool-echo - GNU shtool echo(1) extensional command

SYNOPSIS

       shtool echo [-n|--newline] [-e|--expand] string

DESCRIPTION

       shtool echo is an echo(1) style command which prints string to stdout and optionally provides special expansion constructs (terminal bold
       mode, environment details, date, etc) and newline control. The trick of this command is that it provides a portable -n option and hides the
       gory details needed to find out the environment details under option -e.

OPTIONS

       The following command line options are available.

       -n, --newline
	   By default, output is written to stdout followed by a "newline" (ASCII character 0x0a). If option -n is used, this newline character is
	   omitted.

       -e, --expand
	   If option -e is used, string can contain special "%x" constructs which are expanded before the output is written. Currently the
	   following constructs are recognized:

	   %B  switch terminal mode to bold display mode.

	   %b  switch terminal mode back to normal display mode.

	   %u  the current user name.

	   %U  the current user id (numerical).

	   %g  the current group name.

	   %G  the current group id (numerical).

	   %h  the current hostname (without any domain extension).

	   %d  the current domain name.

	   %D  the current day of the month.

	   %M  the current month (numerical).

	   %m  the current month name.

	   %Y  the current year.

EXAMPLE

	#   shell script
	shtool echo -n -e "Enter your name [%B%u%b]: "; read name
	shtool echo -e "Your Email address might be %u@%h%d"
	shtool echo -e "The current date is %D-%m-%Y"

HISTORY

       The GNU shtool echo command was originally written by Ralf S.  Engelschall <rse@engelschall.com> in 1998 for Website META Language (WML)
       under the name buildinfo. It was later taken over into GNU shtool.

SEE ALSO

       shtool(1), echo(1).

18-Jul-2008							   shtool 2.0.8 						SHTOOL-ECHO.TMP(1)
All times are GMT -4. The time now is 12:57 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy