Help with bash script

[frippee]

On my laptop, when I close the lid it goes into hibernation. When I reopen the lid, I am no longer connected to the internet. I am currently fixing this problem using the following
script.

rm /etc/dhcpc/dhcpcd-eth0.pid; dhcpcd

This works very well except that after a few times of doing this, I have dhcpcd running on a bunch of different processes. So, I started working on a new script. I'm pretty new to linux and bash and I can't figure out why this script won't run. It throws a syntax error near unexpected token ';'. Any help would be great, and thanks in advance. The following is the new script.

rm /etc/dhcpc/dhcpcd-eth0.pid;
ps > txt.txt;
grep dhcpcd txt.txt > txt1.txt;
cut -c1-5 txt1.txt > txt2.txt;
rm txt.txt txt1.txt;
for i in $(cat txt2.txt);
do kill $i;
dhcpcd

[smolloy]

I think it's because you forgot to include a "done" after your "do".

[smolloy]

Just to let you know that you can compress a lot of this. For example,

ps > txt.txt;
grep dhcpcd txt.txt > txt1.txt;
cut -c1-5 txt1.txt > txt2.txt;

Could become

ps aux | grep dhcpcd | grep -v grep | awk '{print $2}' > txt2.txt

That will strip out any processes running that include the word "dhcpcd" but *not* the word "grep", print the second word on that line (i.e. the pid), and dump it to txt2.txt.

EDIT: You could even include all that (without "> txt2.txt" of course) inside the brackets like this,

for i in $(ps aux | grep dhcpcd | grep -v grep | awk '{print $2}') ; do kill $i ; done

A one line bash-script!

[ghostdog74]

here's another version

ps aux | awk '/dhcpcd/{print $2}' | xargs kill

[frippee]

Thanks for the replies, I got it working.It was because of the missing 'done'. Thanks also for the other examples. I am pretty new to bash so I will definitely check them out to see what makes them tick! Thanks alot!

[smolloy]

here's another version

ps aux | awk '/dhcpcd/{print $2}' | xargs kill

That's much neater than my idea. xargs is such an incredibly useful command!