The following command works perfectly to start DHCP:
# dhcpcd -p eth0 DHCP cannot be stopped once it is started. The following command does not work:
# dhcpcd -k eth0 It returns the following:
dhcpcd[4700]: sending signal 1 to pid 4086 dhcpcd[4700]: dhcpcd not running dhcpcd[4700]: kill: Bad file number Could anyone offer a tip on how to kill DHCP?
A way to dynamically get the PID of the dhcp process, and kill it altogether, would be to run:
su var=$(ps | grep dhcp) kill $(echo -n $var | cut -d " " -f 0) Specifically:
ps (which lists the active processes), filtered by grep with the keyword dhcp, to the variable var;kill to terminate the value contained in the first field (-f 0) of the variable var, by telling cut to separate the fields with a whitespace (-d " "). Not coincidentally, the mentioned value corresponds to the PID of the process dhcpcd.
killall dhcpcd would be a better choice. cut, only the first PID is a candidate for killing. You are encouraged to experiment with it yourself, if you don't believe the correctness of the answer. dhcpd on one, and dhcpcd on the other, then the dhcpd is likely to be started first because it has higher priority during boot, and your command would kill that instead. Also, if dhcpcd has a high PID, the chance is high that you match the grep dhcp command itself, which has terminated by the time kill is called, so it would do nothing in this case. This could be done with awk as well. The commands would be;
su
kill -9 $(ps -e | grep dhcp | awk '{ print $1 }')
Details
su to jump to root shell, kill -9 to force kill ps -e lists all the processes in details, we pipe it through grep dhcp which only outputs anything from ps -e output to dhcp, then we pipe it through awk, the print $1 only prints the contents of the first field, which is the process id of dhcp. And kill will kill the process matching that process id.
var=$(ps | grep dhcp). Then, in a new line, dokill $(echo -n $var | cut -d " " -f 0), and it should kill the process altogether.su -c 'killall dhcpcd'work?