Questions[awk](server)

Note : This is not really a question because I already found the answer but since I didn't find it easily here I will post it so that it can benefit others.

Question : How to read a concatenated PEM file as the one used by apache/mod_ssl directive SSLCACertificateFile ?

Answer (original) (source) :

cat $file|awk 'split_after==1{n++;split_after=0} /-----END CERTIFICATE-----/ {split_after=1} {print > "cert" n ".pem"}'

This can leave an empty file if there's a blank line at the end, such as with openssl pkcs7 -outform PEM -in my-chain-file -print_certs. To prevent that, check the length of the line before printing:

cat $file|awk 'split_after==1{n++;split_after=0}
   /-----END CERTIFICATE-----/ {split_after=1}
   {if(length($0) > 0) print > "cert" n ".pem"}' 

Answer 29/03/2016 :

Following @slugchewer answer, csplit might be a clearer option with :

csplit -f cert- $file '/-----BEGIN CERTIFICATE-----/' '{*}'

a bash commands outputs this:

Runtime Name: vmhba2:C0:T3:L14
Group State: active
Runtime Name: vmhba3:C0:T0:L14
Group State: active unoptimized
Runtime Name: vmhba2:C0:T1:L14
Group State: active unoptimized
Runtime Name: vmhba3:C0:T3:L14
Group State: active
Runtime Name: vmhba2:C0:T2:L14
Group State: active

I'd like to pipe it to something to make it look like this:

Runtime Name: vmhba2:C0:T1:L14 Group State: active 
Runtime Name: vmhba3:C0:T3:L14 Group State: active unoptimized
Runtime Name: vmhba2:C0:T2:L14 Group State: active
[...]

i.e. remove every other newline

I tried ... |tr "\nGroup" " " but it removed all newlines and ate up some other letters as well. thanks

I'm trying to convert an ini file into bash array variables. The sample ini is as below:

[foobar]
session=foo
path=/some/path

[barfoo]
session=bar
path=/some/path

so these become:

session[foobar]=foo
path[foobar]=/some/path
session[barfoo]=bar

and so on.

Right now, I could come up with only this command

awk -F'=' '{ if ($1 ~ /^\[/) section=$1; else if ($1 !~ /^$/) print $1 section "=" $2 }'

Also, another problem is, it doesn't take spaces near = into consideration. I think sed is probably better suited for this job but I don't know how to hold and store a temporary variable for the section name in sed.

So any idea how to do this?

Is there a more efficient way to retrieve the MAC address of a NIC in Linux?

This works:

ip link show dev eth0 | awk ' /link\/ether/ { print $2 }'

but can it be found via something like:

cat /sys/net/something

Is there some easy way to find out mac address of all machines on my network rather than doing an SSH into each and ifconfig | grep HWaddr if there are 300 machines on network I really need some easy solution.