Shell Programming and Scripting

hey guys,

I am trying to get some statistics from a DHCP server, like counting the number of DHCP Discovers from a specific MAC address. The script should count the number of DHCP Discovers and output it, otherwise if it cannot find any , it should output the MAC address and "0".

The first clause I am pretty sure it works, I did test it. The problems when I add the if clause.

I did the script like this :

cat /var/log/messages.2.gz | zgrep 192.160 | zgrep "DHCPDIS" | zgrep 0012DFCFC492 | cut -c7- | cut -d ' ' -f5 | sort | uniq -c | sort -rn >> /my_scripts/LOGS/dhcp_test
if [ " cat /var/log/messages.2.gz | zgrep 192.160 | zgrep "DHCPDIS" | zgrep 0012DFCFC492 | cut -c7- | cut -d ' ' -f5 | sort | uniq -c | sort -rn " -lt "1"];
then echo "0012DFCFC492 0" >> /my_scripts/LOGS/dhcp_test
fi

I am getting this error :

./test.bash: line 2: [: missing `]'

What am I doing wrong ?

Thanks in advance!

I'm not sure what you're even trying to do by putting that giant chunk of stuff in an if-statement, but I'm pretty sure there's a better way to get what you want done than an eight-long pipe chain. You've also got several useless uses of cat thrown in for good measure. And I don't think you're supposed to use several zgrep's in a row like that either, just one is enough to unzip the stream.

What is your input, and what output do you want?

Have you got a space at the end of your test brackets? Yours seems to end with -lt "1"] Without the space bash thinks that the bracket is part of the rest of it.

Corona,

What I try to do is simple : I try to count the number of DHCP discovers for that specific MAC address (0012DFCFC492) and the IP address starting with 192.168.

The initial string looks like this :

Code:

Nov  3 17:01:04 dhcp01 ZEMdhcp: 0012DFCFC492: Got DHCPDISCOVER xid=0x545e01bc from 0.0.0.0 via 192.168.124.1, req-ip=None, 82=(0012DFCFC492, 576F6F1E1201, '192.168.124.1').

I have a lot of this kind of messages in my network, so I decided to count the devices which issue these messages more than 10 times.

This is what actually this line should do :

Code:

cat/var/log/messages.2.gz | zgrep 192.168 | grep "DHCPDIS" |grep 0012DFCFC492 | cut -c7- | cut -d ' ' -f5  | sort | uniq -c | sort -rn >> /my_scripts/LOGS/dhcp_test

The output of this looks like :

Code:

1599 0012DFCFC492

Note that I also use the sort to arrange this count descending.

What can I eliminate from this script till now ?

Next, if no such line is found in the messages file, I want that the script output this :

Code:

0 0012DFCFC492

Did you get my point ?

Code:

cat /var/log/messages.2.gz | zgrep 192.160 | zgrep "DHCPDIS" |
  zgrep 0012DFCFC492 | cut -c7- | cut -d ' ' -f5 | sort | uniq -c |
  sort -rn >> /my_scripts/LOGS/dhcp_test

if [ " cat /var/log/messages.2.gz | zgrep 192.160 | zgrep "DHCPDIS" |
  zgrep 0012DFCFC492 | cut -c7- | cut -d ' ' -f5 | sort | uniq -c |
  sort -rn " -lt "1" ];
then
   echo "0012DFCFC492 0" >> /my_scripts/LOGS/dhcp_test
fi

See the red? I added a space between ] and everything else.

---------- Post updated at 17:19 ---------- Previous update was at 17:10 ----------

Your code has many errors.

zgrep -c [pattern] file.gz will give you a count. You should consider creating a pattern to match several of the criteria all at once. OR. You can use awk to "group them" if you wanted different IP's, for example.

So show us EXACTLY what you want for output, a small sample. You kind of hinted above at what you want.

Hi ,

Thanks, I did that change but still I am getting this error :

./test.bash: line 2: [: too many arguments


What could be wrong ?

---------- Post updated at 01:35 AM ---------- Previous update was at 01:19 AM ----------

Hi,

As I said, I need to count the numbers of DHCP Discovers from the logfile.

Here it is the output :

DHCP01 Test # cat /var/log/messages.2.gz | zgrep 94.18 | grep "DHCPDIS" | grep 0012CFCDA11A | cut -c7- | cut -d ' ' -f5 | sort | uniq -c


3 010012CFCDA11A:

Here is one sample of a line in messages.2.gz :

Nov 3 17:01:04 dhcp01 ZEMdhcp: 010012CFCDA11A: Got DHCPDISCOVER xid=0x545e01bc from 0.0.0.0 via 94.18.124.1, req-ip=None, 82=(0012CFCDA11A ,576F6F1E1201, '94.18.124.6').



So, basically, it counts the number of DHCP discovers for this mac address.

Next, I want to create a script to put the output results in a file. If the command cannot find any discover for a mac address, the output should look like

0 010012CFCDA11A:



The script that I created looks like this :


cat /var/log/messages.2.gz | zgrep 94.18 | zgrep "DHCPDIS" | grep 10012CFCDA11A | cut -c7- | cut -d ' ' -f5 | sort | uniq -c >> /my_scripts/LOGS/dhcp_test

if [ " cat /var/log/messages.2.gz | zgrep 94.18 | grep "DHCPDIS" | grep 10012CFCDA11A | cut -c7- | cut -d ' ' -f5 | sort | uniq -c " -lt "1" ];
then
echo "0 10012CFCDA11A" >> /my_scripts/LOGS/dhcp_test
fi


Thanks,

How about using awk

Code:

zcat /var/log/messages.2.gz | awk -v MAC=0012CFCDA11A -v C=0 '{ if ($0 ~ "DHCPDIS.*94.18.*"MAC ) C++ } END { print C, MAC }'