一般是用crontab -e来增删计划任务，如果要导入任务，则可以通过复制文件的方式来操作

Mac OS X – /usr/lib/cron/tabs/ (user cron location /usr/lib/cron/tabs/vivek)
FreeBSD/OpenBSD/NetBSD – /var/cron/tabs/ (user cron location /var/cron/tabs/vivek)
CentOS/Red Hat/RHEL/Fedora/Scientific Linux – /var/spool/cron/ (user cron location /var/spool/cron/vivek)
Debian / Ubuntu Linux – /var/spool/cron/crontabs/ (user cron location /var/spool/cron/crontabs/vivek)
HP-UX Unix – /var/spool/cron/crontabs/ (user cron location /var/spool/cron/crontabs/vivek)
IBM AIX Unix – /var/spool/cron/ (user cron location /var/spool/cron/vivek)