I had created a nohup service using the below command in putty.
nohup php /var/www/html/XYZ/sample.php &
This command executes the sample.php file in background.
Now what i need is i want a shell script which checks whether this service is running or not.Incase if the service is not running i want that shell script to create a service by its own. Below is the code what i tried.
#!/bin/bash
email_to="xyz#gmail.com";
export DISPLAY=:0.0
PIDS=`ps -aux | grep sample.php|awk '{print $2}'`
if [ -z "$PIDS" ]; then
echo "$(date) - The service is not running. Sending email to :$email_to" >> /var/www/html/XYZ/sample.php;
echo "SERVICE is not running - $(date)" | mail -s "service is not running - $(date)" $email_to
echo "" >> /var/www/html/XYZ/sample.php;
exit 1
else
echo "$(date) - Service already running. Sending email to : $email_to" >> /var/www/html/XYZ/sample.php;
echo "SERVICE is running - $(date)" | mail -s "SERVICE is running - $(date)" $email_to
fi
when i execute the file i get the mail as service is running ,and once i kill the sample.php and when i get execute this file i get the same mail "as service is running" but its wrong ,so can anyone direct me where have i gone wrong?
where have i gone wrong?
With ps -aux | grep sample.php, the grep is finding sample.php in its own process command line grep sample.php, also output by ps. This can be avoided by modifying the grep command so that it doesn't contain sample.php literally, e. g. grep 'sample\.php' (which by the way averts the risk of matching another character instead of the .). You'll probably also need wide output from ps to not truncate the command, so change the above pipeline to ps waux | grep 'sample\.php'.
Related
What is the best way in bash to check if a service is installed? It should work across both Red Hat (CentOS) and Ubuntu?
Thinking:
service="mysqld"
if [ -f "/etc/init.d/$service" ]; then
# mysqld service exists
fi
Could also use the service command and check the return code.
service mysqld status
if [ $? = 0 ]; then
# mysqld service exists
fi
What is the best solution?
To get the status of one service without "pinging" all other services, you can use the command:
systemctl list-units --full -all | grep -Fq "$SERVICENAME.service"
By the way, this is what is used in bash (auto-)completion (see in file /usr/share/bash-completion/bash_completion, look for _services):
COMPREPLY+=( $( systemctl list-units --full --all 2>/dev/null | \
awk '$1 ~ /\.service$/ { sub("\\.service$", "", $1); print $1 }' ) )
Or a more elaborate solution:
service_exists() {
local n=$1
if [[ $(systemctl list-units --all -t service --full --no-legend "$n.service" | sed 's/^\s*//g' | cut -f1 -d' ') == $n.service ]]; then
return 0
else
return 1
fi
}
if service_exists systemd-networkd; then
...
fi
Hope to help.
Rustam Mamat gets the credit for this:
If you list all your services, you can grep the results to see what's in there. E.g.:
# Restart apache2 service, if it exists.
if service --status-all | grep -Fq 'apache2'; then
sudo service apache2 restart
fi
On a SystemD system :
serviceName="Name of your service"
if systemctl --all --type service | grep -q "$serviceName";then
echo "$serviceName exists."
else
echo "$serviceName does NOT exist."
fi
On a Upstart system :
serviceName="Name of your service"
if initctl list | grep -q "$serviceName";then
echo "$serviceName exists."
else
echo "$serviceName does NOT exist."
fi
On a SysV (System V) system :
serviceName="Name of your service"
if service --status-all | grep -q "$serviceName";then
echo "$serviceName exists."
else
echo "$serviceName does NOT exist."
fi
In systemd (especially in Debian), it doesn't seems to work properly using the various answers from here. For some services like pure-ftpd if it's in disabled mode, it will not show up in service list when you trigger this command:
systemctl --all --type service
and when you start again the pure-ftpd with systemctl start pure-ftpd the list will appear again. So listing the service using systemctl --all --type service will not work for all services. Take a look at this for more information.
So, this is the best code so far (improvement from #jehon's answer) to check if a service is exist (even it has status inactive, dead or whatever status it is):
#!/bin/bash
is_service_exists() {
local x=$1
if systemctl status "${x}" 2> /dev/null | grep -Fq "Active:"; then
return 0
else
return 1
fi
}
if is_service_exists 'pure-ftpd'; then
echo "Service found!"
else
echo "Service not found!"
fi
Explanation:
If systemctl status found a service, it must have a text 'Active:' we filter using grep and it would return 0. If there is no 'Active:' text it would return 1.
If systemctl status does not find the 'Active:' text, it will print out a standard error. So, I put redirection 2> /dev/null to redirect the standard error. For example, if you are looking for the non existence service, you would get this error message if you don't put that error redirection:
Unit pure-ftpdd.service could not be found.
We don't want to have the above standard error message if you are doing scripting
EDIT:
Another method is to list out unit files which able to detect disabled service as pointed by #Anthony Rutledge for Debian system:
systemctl list-unit-files --type service | grep -F "pure-ftpd"
But using this method will not always work especially for older system because some unit files might not be detected using this command as explained in here. Also, using this method is slower if you have large unit-files that need to be filtered (as commented by #ygoe about heavy load on a small computer).
To build off of Joel B's answer, here it is as a function (with a bit of flexibility added in. Note the complete lack of parameter checking; this will break if you don't pass in 2 parameters):
#!/bin/sh
serviceCommand() {
if sudo service --status-all | grep -Fq ${1}; then
sudo service ${1} ${2}
fi
}
serviceCommand apache2 status
After reading some systemd man pages ...
https://www.freedesktop.org/software/systemd/man/systemd.unit.html
... and systemd.services(5)....
... and a nice little article ...
https://www.linux.com/learn/understanding-and-using-systemd
I believe this could be an answer.
systemctl list-unit-files --type service
Pipe to awk {'print $1'} to just get a listing of the service units.
Pipe to awk again to get the service names exclusively. Change the field separator to the period with -F.
awk -F. {'print $1'}
In summary:
systemctl list-unit-files --type service | awk {'print $1'} | awk -F. {'print $1'}
With variation and augmentation of the base solution, you can determine the state of your system's services by combining a for loop with systemctl is-active $service.
#!/bin/sh
service=mysql
status=$(/etc/init.d/mysql status)
print "$status"
#echo $status > /var/log/mysql_status_log
var=$(service --status-all | grep -w "$Service")
if [ "output" != "" ]; then
#executes if service exists
else
#executes if service does not exist
fi
$Service is the name of the service you want to know if exists.
var will contain something like
[+] apache2
if the service does exist
if systemctl cat xxx >/dev/null 2>&1; then
echo yes
fi
Try this, as ps command can be used in both Ubuntu&RHEL, this should be work in both platform.
#!/bin/bash
ps cax | grep mysqld > /dev/null
if [ $? -eq 0 ]; then
echo "mysqld service exists"
else
echo "mysqld service not exists"
fi
I have a simple shell script where I need to check if my EMR job is running or not and I am just printing a log but it does not seem to work properly when scheduling the script using cron as it always prints the if block statement because the value of "status_live" var is always empty so if anyone can suggest what is wrong here otherwise on manually running the script it works properly.
#!/bin/sh
status_live=$(yarn application -list | grep -i "Streaming App")
if [ -z $status_live ]
then
echo "Running spark streaming job again at: "$(date) &
else
echo "Spark Streaming job is running, at: "$(date)
fi
Your script cannot run in cron because cron script has no environment context at all.
For example try to run your script as another use nobody that has no shell.
sudo -u nobody <script-full-path>
It will fail because it has no environment context.
The solution is to add your user environment context to your script. Just add source to your .bash_profile
sed -i "2a source $HOME/.bash_profile" <script-full-path>
Your script should look like:
#!/bin/sh
source /home/<your user name>/.bash_profile
status_live=$(yarn application -list | grep -i "Streaming App")
if [ -z $status_live ]
then
echo "Running spark streaming job again at: "$(date) &
else
echo "Spark Streaming job is running, at: "$(date)
fi
Now try to run it again with user nobody, if it works than cron will work as well.
sudo -u nobody <script-full-path>
Note that cron has no standard output. and you will need to redirect standard output from your script to a log file.
<script-full-path> >> <logfile-full-path>
# $? will have the last command status in bash shell scripting
# your complete command here below and status_live is 0 if it finds in grep (i.e. true in shell if condition.)
yarn application -list | grep -i "Streaming App"
status_live=$?
echo status_live: ${status_live}
if [ "$status_live" -eq 0 ]; then
echo "success
else
echo "fail"
fi
I want to check if one, (or all) services are running, if yes, stop it
#!/bin/bash
# Define an array of processes to be checked.
# If properly quoted, these may contain spaces
check_process=( "nagios" "httpd" )
for p in "${check_process[#]}"; do
if pgrep "$p" > /dev/null; then
echo "Process \`$p' is running, stopping it"
service $p stop
else
echo "Process \`$p' is not running"
fi
done
For httpd service all works fine, script detects correctly httpd service state.
I have issues detecting nagios service state.
But although nagios service is not running, script shows it's running
Process `nagios' is running, stopping it
Stopping nagios:No lock file found in /usr/local/nagios/var/nagios.lock
Process `httpd' is not running
Is there any more elegant way of detecting if nagios service is running without checking if nagios.lock file exists ?
pgrep nagios shows no output when service is not tunning.
I gave up, this works fine for me:
although ps -ef | grep -v grep | grep $service | wc -l shows 0 for nagios, script reports that nagios service is running
#!/bin/bash
logfile=/tmp/stop_nagios.txt
exec >> $logfile
exec 2>&1
service=httpd
if (( $(ps -ef | grep -v grep | grep $service | wc -l) > 0 ))
then
echo "$service is running, stopping it"
date
sudo service $service stop
else
echo "$service is not running"
fi
# check nagios service
FILE=/usr/local/nagios/var/nagios.lock
if test -f "$FILE"; then
echo "nagios service is running, stopping it"
date
sudo service nagios stop
else
echo "nagios is not running..."
fi
I've done my homework, but I think I may be mixing apples and oranges here. My script is designed to run a remote inline series of commands, exit, and then run some additional LOCAL commands. It has to be done remote first, as these services are for a fail-over agent. The problem is that after the remote ssh line disconnects, the entire script just stops. I'm not sure why the disconnect is halting the entire script. Perhaps the exit line is to blame?
#!/bin/bash
#
### Run remote svc restarts and then Local restarts
#
exec ssh -t REMOTEHOST 'stop svc1; restart svc2; start svc3; exit'
(SCRIPT FAILS HERE)
## Run local shell (This works independently, but not in the entire script)
rst=`pgrep -n failoversvc`
echo "Stopping 1st service at `date | awk '{print $2,$3,$4}'`" && service 1 stop >> SYNCLOG.txt
sleep 2
echo "Restarting 2nd service at `date | awk '{print $2,$3,$4}'`" && service 2 restart >> SYNCLOG.txt
if rst="";then
echo "Starting 3rd service at `date | awk '{print $2,$3,$4}'`" && service 3 start >> SYNCLOG.txt
else
echo "3rd Service PID not found! Check for functionality"
fi
I took a look at but THIS I wasn't able to get the results I was looking for.
exec is a very brutal command: it completely replaces the current process (in this case, your shell that's running the script) with the command you specify. Unless exec fails, nothing after that line in your script will ever run. This is by design, that's what exec is for.
If you want your script to continue after the ssh, simply remove exec.
I am using the following shellscript to check running process in a cron job:
ps -ef|grep myprocess|grep -v "grep"
I then need to send an email if the result is empty(meaning process is not running), how do I script this?
One solution:
pgrep processname &>/dev/null && exit 0
echo |mail -s"Aiie, process processname not running!" mail#addresse.here
Then put it in a crontab like already suggested. Of course, it means you must have the mail command installed.
You can do it this way
PROCESS_FOUND=`ps -ef|grep myprocess|grep -v grep`
if [ "$PROCESS_FOUND" = "" ]
then
#send mail from here ...Process not running
fi