My server is running crontabs of 4 different users.
I want to develop a script that whenever a particular change occurs in a crontab , it is detected and the particular change is noted into a file.
Kindly let me know of suggestions on how it can be achieved.
My algo would be:
1. Make a copy of the file
2. Compare present crontab to copy.
3. Use diff to comapre both files.
4. If change present subtract new file from old one and extract the difference.
Regards
---------- Post updated at 12:05 PM ---------- Previous update was at 10:01 AM ----------
Code:
DIFF=`comm -13 /var/spool/cron/crontabs/jun /var/tmp/temp_crontabs/jun_temp`
#DIFF=`comm -13 /var/tmp/temp_crontabs/jun_temp /var/spool/cron/crontabs/jun`
if [ "$DIFF" == "" ]
then
echo "======================"
echo "No change in crontab"
echo "======================"
else
echo "$DIFF"
echo "$DIFF"|mailx -s "Crontab Change Alert" my-email@id.com
fi
cp /var/spool/cron/crontabs/jun /var/tmp/temp_crontabs/jun_temp
This is what Ive done till now but its not giving me the proper result.
Dear Sir,
Now I use oracle database on AIX server and found some user use iligal program such as development tool logon to my database.
I want to detect the process of illegal program and kill it.
Could you please suggest me to make detect process.
Thank you very much
Pkanonwe. (2 Replies)
i have this script that launches multiple xterm sessionon a CDE. i would like to test the xterm so that when i execute the script using an ordinary terminal it will detect that it will unable to launch the xterm and execute other script instead.
i tried using trap and exit status. maybe i am... (2 Replies)
Hi all,
I need to write a script to write data into cd.
Am using cdrecord command.
i need to implement the following
if ( CD-RW) ( ?? How to find this )
cdrecord blank option
else
cdrecord with out blank option
Now can you please help me to form this statement... (2 Replies)
Hi,
I would like to programmatically find if given OS is SLES 10 / RHEL 3/.RHEL 4/RHEL5 etc ..
For this do we have any library call/sys call? Or should we use any sys. structure which would give me detailed info. Share me if you have any pointers.
Thanks in advance
- Krishna (1 Reply)
Hi all
Just curious , is it possible to detect changes in a file and sent to email .
For ex: demo.conf
I would like to receive an email everytime a particular file(demo.conf) changes and the content added/removed and who did the change (userid). Is it possible.
Thanks
CK (4 Replies)
Hello friends,
I want to write a shell script in bash shell .
Working for the script is to detect any key pressed and disply on screen as
"you have pressed: "
For example if user pressed F5 then a messaged has to be displayed as
"you have pressed F5.
Thank you. (4 Replies)
Hi How would i detect the ip address from where the reboot command been given to linux host.
My linux host details are as below.
# lsb_release -a
LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1-noarch
Distributor ID: EnterpriseEnterpriseServer
Description: ... (1 Reply)
Hi,
Is there command to detect the newly added LUN is linux box. I tried with below commands, but that doesn't work out.
fdisk -l,
fdisk -l | grep Disk
pvscan (5 Replies)
whats the equivalent of detect OS in perl with an if then ?
platform='uname'
if ]; then
alias ls='ls --color=auto'
elif ]; then
alias ls='ls -G'
fi
In perl I see
perl -Mstrict -MEnglish -E 'say $OSNAME'
or
print "$^O"
Please use CODE tags as required by... (1 Reply)
I have set several cron jobs. I recently added a new cron job that copies a file of last day from another server and is executed each day (for example at 04:00 am) but when I check next day the file hasn't been copied.
I'm working in GNU/Linux CentOS (2.6.32) system.
The files that I need to... (23 Replies)
Discussion started by: Ophiuchus
23 Replies
LEARN ABOUT NETBSD
cron
CRON(8) BSD System Manager's Manual CRON(8)NAME
cron -- daemon to execute scheduled commands (ISC Cron V4.1)
SYNOPSIS
cron [-n] [-x debugflags]
DESCRIPTION
cron is normally started during system boot by rc.d(8) framework, if cron is switched on in rc.conf(5).
It will return immediately so you don't have to start it with '&'.
cron searches /var/cron/tabs for crontab files which are named after accounts in /etc/passwd. Crontabs found are loaded into memory. cron
also searches for /etc/crontab which is in a different format (see crontab(5)). Finally cron looks for crontabs in /etc/cron.d if it exists,
and executes each file as a crontab.
When cron looks in a directory for crontabs (either in /var/cron/tabs or /etc/cron.d) it will not process files that:
- Start with a '.' or a '#'.
- End with a '~' or with ``.rpmsave'', ``.rpmorig'', or ``.rpmnew''.
- Are of zero length.
- Their length is greater than MAXNAMLEN.
cron then wakes up every minute, examining all stored crontabs, checking each command to see if it should be run in the current minute. When
executing commands, any output is mailed to the owner of the crontab (or to the user named in the MAILTO environment variable in the crontab,
if such exists).
Events such as START and FINISH are recorded in the /var/log/cron log file with date and time details. This information is useful for a num-
ber of reasons, such as determining the amount of time required to run a particular job. By default, root has an hourly job that rotates
these log files with compression to preserve disk space.
Additionally, cron checks each minute to see if its spool directory's modtime (or the modtime on /etc/crontab or /etc/cron.d) has changed,
and if it has, cron will then examine the modtime on all crontabs and reload those which have changed. Thus cron need not be restarted when-
ever a crontab file is modified. Note that the crontab(1) command updates the modtime of the spool directory whenever it changes a crontab.
The following options are available:
-x This flag turns on some debugging flags. debugflags is comma-separated list of debugging flags to turn on. If a flag is turned on,
cron writes some additional debugging information to system log during its work. Available debugging flags are:
sch scheduling
proc process control
pars parsing
load database loading
misc miscellaneous
test test mode - do not actually execute any commands
bit show how various bits are set (long)
ext print extended debugging information
-n Stay in the foreground and don't daemonize cron.
Daylight Saving Time and other time changes
Local time changes of less than three hours, such as those caused by the start or end of Daylight Saving Time, are handled specially. This
only applies to jobs that run at a specific time and jobs that are run with a granularity greater than one hour. Jobs that run more fre-
quently are scheduled normally.
If time has moved forward, those jobs that would have run in the interval that has been skipped will be run immediately. Conversely, if time
has moved backward, care is taken to avoid running jobs twice.
Time changes of more than 3 hours are considered to be corrections to the clock or timezone, and the new time is used immediately.
SIGNALS
On receipt of a SIGHUP, the cron daemon will close and reopen its log file. This is useful in scripts which rotate and age log files. Natu-
rally this is not relevant if cron was built to use syslog(3).
FILES
/var/cron/tabs cron spool directory
/etc/crontab system crontab file
/etc/cron.d/ system crontab directory
/var/log/cron log file for cron events
SEE ALSO crontab(1), crontab(5)AUTHORS
Paul Vixie <vixie@isc.org>
BSD October 12, 2011 BSD