Shell Script
 

Ok. I am fairly new to Linux and have even less experience writing shell scripts. I was recently promoted to a position in IT and am being trained to get familiar with the system. What I am trying to do is write a script that other scripts can call and tell it to write a log file for that script. I also need it to be able to tell when the current log is full and for it to create a new log file. I will have a total of 5 log files at one time. When the current one gets full it will be replaced by the new one and the last one will fall out. Any help in getting me started will be greatly appreciated.

Thanks

I am no scripting guru, but I think you need to clarify some points.

1) What I am trying to do is write a script that other scripts can call and tell it to write a log file for that script.

When a script runs it can create a log file by itself. It doesnt need to call another script to do this. It can be something as simple as redirecting output to a file. Read more about redirection here:
http://tldp.org/LDP/abs/html/io-redirection.html

2) I also need it to be able to tell when the current log is full and for it to create a new log file.

What is full? A log file is never really full unless of course you fill your disk up. A log file can just keep growing. I think what your suggesting is log rotation. When a log reaches a certain size (say 250MB) then you can create another log file.

Some daemons have this built in, you can tell then to rotate the log when it reaches a certain size. Scripts are different from daemons because the usually run once or are set in cron to run multiple times per day, they do no continuously run.

You can check the size of the file at the beginning of the script, if it is over a certain size you can rotate it. Something like this:

#!/bin/bash
DATE = `date +%m-%d-%y`
LOGSIZE=`du -h /path/to/log`
if [ $LOGSIZE > 2048000 ]; then
mv /path/to/log /path/to/log.$DATE
touch /path/to/log
fi

I hope that gets you started. If your new to Linux your better off learning the basics before learning scripting.

Savona,

Thank you. The last part is what I was refering too. I do need to rotate the log files. The other part I am trying to do is have a script that will write output from another script to a log file when it is called upon to do so without having to do it manually. I do know most of the basic but, alot of the functions still confuse me.

Its hard to help you unless I know the script. Is it something you can post?

Or you could write a logging function and put it in a "bash library" file that all the other scripts could source.

For log rotation, use the default tool http://linux.die.net/man/8/logrotate which you should find in /etc

logrotate.conf - basic conf

logrotate.d - dir with separate cfg for each logfile to rotate.

Ok. How would I go about doing this?

This is the directory and the scripts it contains.

taipso75@taipso75:/taipso75/scripts/IPSM >
IPSM_DB_LINKS.sh* IPSM_KM_TCP_daily.sh* IPSM_PROC_CHECK_daily.sh* IPSM_DB_PERFORMANCE_daily.sh* IPSM_KM_TCP.sh* IPSM_PROC_CHECK.sh* IPSM_DB_PERFORMANCE.sh* IPSM_KM_VT_daily.sh* IPSM_PROC_DUPLICATE_daily.sh* IPSM_DB_PING_daily.sh* IPSM_KM_VT.sh* IPSM_PROC_DUPLICATE.sh*
IPSM_DB_PING.sh* IPSM_NETWORK_PING_auto_gen.sh* IPSM_PROC_OLD.sh*
IPSM_DB_SELECT_daily.sh* IPSM_NETWORK_PING_daily.sh* IPSM_SERVERHEALTH_CPU.sh*
IPSM_DB_INVALIDOBJ_daily.sh* IPSM_DB_SELECT.sh* IPSM_NETWORK_PING.sh* IPSM_SERVERHEALTH_daily.sh*
IPSM_DB_INVALIDOBJ.sh* IPSM_DB_TIME_daily.sh* IPSM_PAI_PRINTER_daily.sh* IPSM_SERVERHEALTH_DISKSPACE.sh*
IPSM_DB_JOBS_daily.sh* IPSM_DB_TIME.sh* IPSM_PAI_PRINTER.sh* IPSM_SERVERHEALTH_MEM.sh*
IPSM_DB_JOBS.sh* IPSM_KM_SPOOLS_daily.sh* IPSM_PAI_TELEGRAM_daily.sh* IPSM_WEBSERVER_PING_daily.sh*
IPSM_DB_LINKS_daily.sh* IPSM_KM_SPOOLS.sh* IPSM_PAI_TELEGRAM.sh* IPSM_WEBSERVER_PING.sh*

In each script that you want to use common functions, insert something like this:
The source command reads whatever is in my_bash_library, exactly as if it were in the calling script at that point.

So I need multiple sacripts to do this?

Yes. Instead of "write a script that other scripts can call and tell it to write a log file", you would put a function in a bash library that would "write a log file" and source it from the "other scripts".

I am really lost here. I do appreciate the help. I will do some research this weekend. Thanks

Ok after some research and browsing through current script on my system this is what I have. Please review and give me some input!!!

I am trying to write a script that can be called by other scripts to print output to a log. I also want to be able to rotate the log file for this script with a max of 5 logs files. This is what I have so far:

#/bin/ksh

. /taipso75/scripts/IPSM_run_profile.sh*
log=${IPSM_HOME}/log
(
echo "----------------------------------------------------------------------"
echo "Log on" $0 "am" `date '+%Y-%m-%d %H:%M:%S'`
echo "------------------"
IPSM_LOG_DIR=${IPSM_HOME}/log
date=`date '+%Y-%m-%d'`
yesterday=`date --date='1 days ago' +%F`
cd ${IPSM_HOME}/log
ls -lt | grep ".txt" | cut -c 37-47 | sort -u | grep -vE "${date}|${yesterday}" | while read crea_date; do
tar_files=`ls -ltr *.txt | grep " ${crea_date} " | cut -c 54-`
tgz=${crea_date}.tgz
echo tar cfz ${tgz} ${tar_files}
tar cfz ${tgz} ${tar_files}
ls -ltr *.txt | grep " ${crea_date} "
ls -ltr *.txt | grep " ${crea_date} " | while read del_files; do
del_file=`echo ${del_files} | awk '{print $NF}'`
#echo ${del_file}
rm ${del_file}
done
echo "------------------"
done
# Delete the *.tgz-Files older than 30 days
while [ `ls -l *.tgz | wc -l` -gt 20 ]; do
rm=`ls -r *.tgz | tail -1`
echo ${rm} "have been deleted!"
rm -rf ${rm}
done
) >> ${IPSM_HOME}