what does command test -x do in ubuntu?

问题

what does test -x from /etc/cron.daily/logrotate do?

test -x /usr/sbin/logrotate || exit 0
/usr/sbin/logrotate /etc/logrotate.conf

Does it test if already executing file /usr/sbin/logrotate?

回答1:

test -x /path/to/file

It checks if file exists and is executable by current user

回答2:

Type man test in Google and it will find you a manual page that says this:

'-x file'
     True if file is executable.

来源：https://stackoverflow.com/questions/34704494/what-does-command-test-x-do-in-ubuntu