laravel schedule:run is not working on server(via cron jobs)

What doesn't work? The actual artisan command, or cron not executing the command? If the latter, make sure you're using the proper crontab syntax. You need to specify the frequency using the first 5 parameters.

To have it run every minute (pretty common practice I'd think), you would want this for your crontab entry:

* * * * * /usr/local/bin/php /home/nemanu/root1/artisan schedule:run >> /dev/null 2>&1 

Also, make sure that the php executable actually exists within /usr/local/bin Usually, it resides within /usr/bin/

You can try using the which command to locate where your executable is: $ which php

Yes I have set up the frequency in cpanel. As I am using shared hosting how do I check php executable?

When I run schedule run command from cotroller it works fine. But in cronjobs does not work. I gave the following command to see log file but file is empty:

/usr/local/bin/php /home/nemanu/root1/artisan schedule:run 1>> /home/nemanu/public_html/log_laravel 2>&1

Note:Before changing the hosting I was able to change the root but now I cant. If I do shows no specified file error which I could not resolved. So I had to keep public file in public_html folder and rest of them in /root1. I mentioned it thinking if it is related somehow.

@thomaskim could you give me a solution?

After a bit of analysis I have found that every time the cron is running it gives me a error in error log:

[15-Feb-2019 03:51:01 UTC] PHP Parse error:  syntax error, unexpected '?' in /home/nemanu/root1/vendor/laravel/framework/src/Illuminate/Foundation/helpers.php on line 233

I am using php 7.1

No, the php you are using for the Cron is an older version.

You probably need to ask your hosting provider to tell you where you can find the 7.1 cli version