I have a crontab job set up which records the speed of my network every two minutes:
*/2 * * * * /usr/local/bin/speedtest >> ~/Documents/speedtest.log
The output is saved to speedtest.log:
Testing download speed................................................................................
Download: 60.10 Mbit/s
Is there a way to add a timestamp (the format given is an example only; the actual format is irrelevant) to each entry to achieve something like this?
20200125221000: Testing download speed................................................................
20200125221042: Download: 60.10 Mbit/s
If so, how?
You can do:
*/2 * * * * echo "$(/usr/local/bin/speedtest) $(date)" >> ~/Documents/speedtest.log
I want to check to see if the line exists with a script:
*/2 * * * * ls -1 /var/www/html/shared-media > /var/www/html/files.txt
I also need a way to remove that SPECIFIC line in the same script.
when I am trying to execute flock through cron job I am getting error.
I am executing
* * * * * /usr/bin/flock -n /usr/local/monitor/asdp_cloudwatch/run_asdp0101.sh
and I am getting below error
/usr/bin/flock: bad number: /usr/local/monitor/asdp_cloudwatch/run_asdp0101.sh
Can anyone solve this. Help can be appreciated.
flock needs a lock file and a command to run. You've only specified one argument. I'm assuming that it is the command, so must also specify the command to run. Something like that:
* * * * * /usr/bin/flock -n /path/to/lockfile /usr/local/monitor/asdp_cloudwatch/run_asdp0101.sh
You need to adjust /path/to/lockfile of course.
I have several scripts that are run every 3 minutes and schedule looks like this:
*/3 * * * * /some/script1.php
*/3 * * * * /some/script2.php
*/3 * * * * /some/script3.php
I suppose that these scripts run at the same time, but I wish that these scripts run every 3 minute but not in the same time. Tell me please how can I reach this.
You can't reach that with the lines you are having, those will allways be running at the same times. However, you can simply create one "master" script that gets called via cron and then calls the scripts one after the other.
*/3 * * * * /usr/bin/php /some/masterscript.php
masterscript.php:
<?php
exec('/usr/bin/php /some/script1.php');
exec('/usr/bin/php /some/script2.php');
exec('/usr/bin/php /some/script3.php');
?>
EDIT:
Depending on your server's setup - install node.js. There's a cron package you can set for every second. Maybe this can help..
You can but not with that syntax, instead you should use this kind of syntax:
1,4,7,10,13,16,etc... * * * * /some/script1.php
2,5,8,11,14,17,etc... * * * * /some/script2.php
and so on....
If you just want each script to execute in turn, with the second not starting until the first has finished, and so forth, just put them all in a single cron command.
cron invokes each command by passing the command string to /bin/sh -- and the shell can very easily invoke several commands in sequence.
*/3 * * * * /some/script1.php ; /some/script2.php ; /some/script3.php
do you think a couple of seconds between scripts run could be enough ?
what about a command like this ?
*/3 * * * * echo "<?php echo 'Start ...';sleep(2);echo Go; ?>"|php /some/script1.php
*/3 * * * * echo "<?php echo 'Start ...';sleep(4);echo Go; ?>"|php /some/script2.php
*/3 * * * * echo "<?php echo 'Start ...';sleep(6);echo Go; ?>"|php /some/script3.php
You could also substitute fixed waiting time with random waiting time.
Instead of sleep(2) try a generic sleep(rand(1,10)).
I hope this could be useful
I need to make a crontab to gzip a file named mh located on my desktop every 2 minutes in the same path. I tried
2 * * * * gzip home/Desktop/mh >> home/Desktop
But it is not working, any help is greatly appreciated.
There are several errors here.
The gzip command should be simply gzip home/Desktop/mh. Remove the >> and everything afterwards.
Your current cron will only run on the second minute of every hour. Instead you want */30 * * * * ... to run 30 times per hour.
Note that gzip is "destructive" in the sense that your original file (mh) will disappear after each gzip. That would be bad if some other process is trying to write to it continually...
If you want to keep the content of mh and just update mh.gz from it periodically, you want to do
*/30 * * * * gzip < /home/Desktop/mh > /home/Desktop/mh.gz