[SOLVED] awk regex magic (match first occurrence of character in each line)

Issue

Have been scratching my head over this one, hoping there's a simple solution that I've missed.

Summary

Simplified the following code can't cope with IPv6 addresses in the (here abbreviated) apache log parsed to it. Do I SED the variable before parsing to AWK or can I change the AWK regex to match only the first ":" on each line in $clog?

$ clog='djerk.nl:80 200.87.62.227 - - [20/Nov/2015:01:06:25 +0100] "GET /some_url HTTP/1.1" 404 37252
bogus.com:80 200.87.62.227 - - [20/Nov/2015:01:06:27 +0100] "GET /some_url HTTP/1.1" 404 37262
djerk.nl:80 200.87.62.227 - - [20/Nov/2015:01:06:29 +0100] "GET /another_url HTTP/1.1" 200 11142
ipv6.com:80 2a01:3e8:abcd:320::1 - - [20/Nov/2015:01:35:24 +0100] "GET /some_url HTTP/1.1" 200 273'

$ echo "$clog" | awk -F '[: -]+' '{ vHost[$1]+=$13 } END { for (var in vHost) { printf "%s %.0f\n", var, vHost[var] }}'
> bogus.com 37262
> djerk.nl 48394
> ipv6.com 0

As can be seen the last line of variable $clog, the vhost domain is caught but not the byte count which should come out at 273 instead of 0.

Original long question

The problem I have is with the ":" character. In addition to the other two characters (space and dash), I need AWK to match only the first occurrence of ":" in each line it's evaluating. the following splits each line by three characters which works fine, until the log entries contain IPv6 addresses.

matrix=$( echo "$clog" | awk -F '[: -]+' '{ vHost[$1]++; Bytes[$1]+=$13 } END { for (var in vHost) { printf "%s %.0f %.0f\n", var, vHost[var], Bytes[var] }}' )

The above code converts the following log entries (contained in variable $clog):

djerk.nl:80 200.87.62.227 - - [20/Nov/2015:01:06:25 +0100] "GET /some_url HTTP/1.1" 404 37252 "-" "Safari/11601.1.56 CFNetwork/760.0.5 Darwin/15.0.0 (x86_64)"
bogus.com:80 200.87.62.227 - - [20/Nov/2015:01:06:27 +0100] "GET /some_url HTTP/1.1" 404 37262 "-" "Safari/11601.1.56 CFNetwork/760.0.5 Darwin/15.0.0 (x86_64)"
djerk.nl:80 200.87.62.227 - - [20/Nov/2015:01:06:29 +0100] "GET /wordpress/2014/ssl-intercept-headaches HTTP/1.1" 200 11142 "-" "Mozilla/5.0 (iPhone; CPU iPhone OS 8_1 like Mac OS X) AppleWebKit/600.1.4 (KHTML, like Gecko) Version/8.0 Mobile/12B410 Safari/600.1.4"
djerk.nl:80 200.87.62.227 - - [20/Nov/2015:01:06:30 +0100] "GET /some_other_url HTTP/1.1" 404 37264 "-" "Safari/11601.1.56 CFNetwork/760.0.5 Darwin/15.0.0 (x86_64)"

Into a table like so, containing vhost name (sans TCP port number), hits and cumulative byte count. One line per vhost:

djerk.nl 3 85658
bogus.com 1 37262

But IPv6 addresses get unintentionally split due to their notation and this causes AWK to produce bogus output when evaluation these log entries. Sample IPv6 log entry:

djerk.nl:80 2a01:3e8:abcd:320::1 - - [20/Nov/2015:01:35:24 +0100] "POST /wordpress/wp-cron.php?doing_wp_cron=*** HTTP/1.0" 200 273 "-" "WordPress; http://www.djerk.nl/wordpress"

I guess a work around would be to mangle variable $clog to replace the first occurrence of ":" and remove this character from the AWK regex. But I don't think native bash substitution is capable of negotiating variables with multiple lines.

clog=$(sed 's/:/ /' <<< "$clog")
matrix=$( echo "$clog" | awk -F '[ -]+' '{ vHost[$1]++; Bytes[$1]+=$10 } END { for (var in vHost) { printf "%s %.0f %.0f\n", var, vHost[var], Bytes[var] }}' )

This works because $clog is quoted which preserves the line feeds and runs sed on each line individually. As a result (and shown) the AWK line needs to be adjusted to ignore ":" and grab $10 instead of $13 for the byte count.

So as it turns out, in writing this, I've already given myself a solution. But I'm sure someone will know of a better more efficient way.

Solution

Just don't split the entire line on colons. Remove the port number from the field you extract instead.

split($1, v, /:/); vHost[v[1]]++; ...

I don't see why you would split on dashes, either; either way, the field numbers will be renumbered, so you would end up with something like

awk '{ split($1, v, /:/); vHost[v[1]]++; Bytes[v[1]]+=$11 }
   END { for (var in vHost)
        printf "%s %.0f %.0f\n", var, vHost[var], Bytes[var] }'

Answered By - tripleee

Answer Checked By - Mildred Charles (WPSolving Admin)