Cyclades PC400 installation manual Active root /etc/tstcron.src, 59 * * * * /etc/testcron.sh

Cyclades-PC400 Installation Manual

•status (active or inactive) - if this item is not active, the script will not be executed.

•user - the process will be run with the privileges of this user, who must be a valid local user.

•source - pathname of the crontab file.

When the /etc/crontab_files file contains the following line:

active root /etc/tst_cron.src

and the /etc/tst_cron.src file contains the following line:

0-59 * * * * /etc/test_cron.sh

crond will execute the script listed in tst_cron.sh with root privileges each minute.

Another option is to use the crontab command to interactively modify the crontab file. Its syntax is: crontab [-u user] file or crontab [-u user] { -e -l -r }

where

-e = edit user’s crontab -l = list user’s crontab

-r = delete user’s crontab

Type man cron and man crontab at the Linux prompt for more information.

The DHCP (Dynamic Host Configuration Protocol) Client

DHCP is a protocol that allows network administrators to assign IP addresses automatically to network devices. Without DHCP (or a similar protocol like BOOTP), each device would have to configured manually. DHCP automatically sends a new IP address to a connected device when it is moved to another location on the network. DHCP uses the concept of a fixed time period during which the assigned IP address is valid for the device it was assigned for. This “lease” time can vary for each device. A short lease time can be used when there are more devices than available IP numbers. For more information on how to set your server up as a DHCP client or server, see RFC 2131 or the DHCP pages at www.linuxdoc.org

Appendix A - Linux 40