Sponsored Content
Top Forums Shell Programming and Scripting piping and backgroud processes (daemons) Post 302207233 by demwz on Thursday 19th of June 2008 11:19:59 AM
Old 06-19-2008
piping and backgroud processes (daemons)

Hello to all,
I've a strage problem here:
a perl script that parses the output of sar -q 300 0 (one line of performace data each 5 min. infinately) works fine from the CLI. It processes one line output every 5 minutes.
If i disconnect it from the terminal (executing it with cron, nohup startporc etc...) no output is processed until sar has completed (using sar -q 1 20).
then all 20 llines output are processed at the same time.

Code
Quote:
open (SAR,"/usr/bin/sar -q 1 4&|") or die "Cant open sar" ;
while (<SAR>){
chomp;
# write the output into a rrd database
}
close (SAR);
the script is supposed to run as "demon" in the backdround to ubdate
performance reports every 5 minutes, so i need to process the output just in time.

As far as i foun out it is not a Perl problem rather than the way linux handels pipes on processes not running on a terminal.

any ideas ?
 

9 More Discussions You Might Find Interesting

1. IP Networking

DNS daemons

Does anyone know the command to start the DNS Daemon. I looked in the /etc/init.d/inetsvc file and it tells me what the text should look like. When I go to open the corresponding files they are encoded and I can't read them. So is there a command that will start the DNS daemon? If... (8 Replies)
Discussion started by: Deuce
8 Replies

2. UNIX for Advanced & Expert Users

backgroud process

Hi experts How to write a shell program(sh) that running on the backgroud when foreground processing something, such as prompt ....... till the background process finished. thx (4 Replies)
Discussion started by: trynew
4 Replies

3. UNIX for Dummies Questions & Answers

Daemons

MYSQL-daemon don't started automatically by system-start. And same trouble with httpd too. I have SuSE 8.0. What can I do ? Thanks.... (6 Replies)
Discussion started by: Pennywize
6 Replies

4. Linux

A doubt on Daemons

Hi there! I'm a bit curious on something about Daemons.... Supose you have two processes say A and B, where B is a daemon. A is totally independent from B. Is there a way for A to find out B's return code? Is there a way for A to find out when B ends? Thanks! (4 Replies)
Discussion started by: marioh
4 Replies

5. UNIX for Dummies Questions & Answers

Starting daemons at reboot.

I rebooted my server (solaris 5.8) and I had to manually start the cron and mailx daemons. How do I get these to automatically start at reboot? Thanks in advance. (2 Replies)
Discussion started by: shorty
2 Replies

6. Shell Programming and Scripting

daemons definition

hi there, can somebody give me a definition for daemons, or example what are they !! and what the use for? i've done some research and all what i found is /etc/... or /usr/bin/... and i haven't quietly got the concept. any ideas !! Thanks. (5 Replies)
Discussion started by: new2Linux
5 Replies

7. Shell Programming and Scripting

multiple child scripts running in backgroud, how to use grep on the parent?

Hi I have a shell script A which calls another 10 shell scripts which run in background. How do i make the parent script wait for the child scripts complete, or in other words, i must be able to do a grep of parent script to find out if the child scripts are still running. My Code: ... (5 Replies)
Discussion started by: albertashish
5 Replies

8. HP-UX

status of daemons

Hi there all, Hey, is there a way to get the status of all daemons running on a HPUX? in an easy way? Like the same way how to vieuw the status of packages in cmviewcl. Thanks! (1 Reply)
Discussion started by: draco
1 Replies

9. Shell Programming and Scripting

Running commands in backgroud

I have a small question may be this will be discussed before I have two files file1 and file2 with huge data and I am running the commands as cat file1 |sort & cat file2 |sort & If the session is got disconnected or logout will this command run in background, or shall we use nohup (3 Replies)
Discussion started by: morbid_angel
3 Replies
sag(1)                                                             User Commands                                                            sag(1)

NAME
sag - system activity graph SYNOPSIS
sag [-e time] [-f file] [-i sec] [-s time] [-T term] [-x spec] [-y spec] DESCRIPTION
The sag utility graphically displays the system activity data stored in a binary data file by a previous sar(1) run. Any of the sar data items may be plotted singly or in combination, as cross plots or versus time. Simple arithmetic combinations of data may be specified. sag invokes sar and finds the desired data by string-matching the data column header (run sar to see what is available). The sag utility requires a graphic terminal to draw the graph, and uses tplot(1) to produce its output. When running Solaris 2.x and OpenWindows, perform the following steps: 1. Run an "xterm" as a Tektronics terminal: prompt# xterm -t 2. In the "xterm" window, run sag specifying a tek terminal: prompt# sag -T tek options OPTIONS
The following options are supported and passed through to sar (see sar(1)): -e time Select data up to time. Default is 18:00. -f file Use file as the data source for sar. Default is the current daily data file /usr/adm/sa/sadd. -i sec Select data at intervals as close as possible to sec seconds. -s time Select data later than time in the form hh[:mm]. Default is 08:00. -T term Produce output suitable for terminal term. See tplot(1) for known terminals. Default for term is $TERM. -x spec x axis specification with spec in the form: name[op name]...[lo hi] name is either a string that will match a column header in the sar report, with an optional device name in square brackets, for example, r+w/s[dsk-1], or an integer value. op is + - * or / surrounded by blank spaces. Up to five names may be specified. Parentheses are not recognized. Contrary to custom, + and - have precedence over * and /. Evaluation is left to right. Thus, A/A+B*100 is evaluated as (A/(A+B))*100, and A+B/C+D is (A+B)/(C+D). lo and hi are optional numeric scale limits. If unspecified, they are deduced from the data. Enclose spec in double-quotes ("") if it includes white space. A single spec is permitted for the x axis. If unspecified, time is used. -y spec y axis specification with spec in the same form as for -x. Up to 5 spec arguments separated by a semi-colon (;) may be given for -y. The -y default is: -y"%usr0100;%usr+%sys0100;%usr+%sys+%wio0100" EXAMPLES
Example 1: Examples of the sag command. To see today's CPU utilization: example$ sag To see activity over 15 minutes of all disk drives: example$ TS=`date +%H:%M` example$ sar -o /tmp/tempfile 60 15 example$ TE=`date +%H:%M` example$ sag -f /tmp/tempfile -s $TS -e $TE -y "r+w/s[dsk]" FILES
/usr/adm/sa/sadd daily data file for day dd ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWaccu | +-----------------------------+-----------------------------+ SEE ALSO
sar(1), tplot(1), attributes(5) SunOS 5.10 4 Mar 1998 sag(1)
All times are GMT -4. The time now is 11:31 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy