readme.md

file before:

some
stuff
at the top
              <------------------------ place of pasting text with line_before
table ....    <-------------------+
table ....                        |
table ....                        |
                                  |
nat...                            |
nat...                            +----- section matched by multiline regexp
                                  |
block ...                         |
block ...                         |
                                  |
pass...                           |
pass...       <-------------------+
              <------------------------ place of pasting text with line_after
some stuff below
the file

file after:

some
stuff
at the top

# This is some
# multiline text
# injected into file
# with insert_before
table ....
table ....
table ....

nat...
nat...

block ...
block ...

pass...
pass...
# This is some
# multiline text
# injected into file
# with insert_after

some stuff below
the file

utils.subr

#!/bin/sh

# INSERT LINES AFTER A PATTERN
insert_after () {
	filename=$1
	pattern=$2
	text=$3
	size=$(cat $filename | wc -l)

        patched=$(pcregrep -Mine "${pattern}${text}" $filename | wc -l)
	if [ $patched -gt 0 ]; then echo "already patched, skipping..."; return; fi

	match=$(pcregrep -Mine "$pattern" $filename)
	msize=$(pcregrep -Mine "$pattern" $filename | wc -l)
	start=$(echo $match | cut -d: -f1)
	end=$(( $start + $msize ))

	sed "${end}i\\
${text}" $filename > /tmp/ppf.tmp
	mv /tmp/ppf.tmp $filename
}

# INSERT LINES BEFORE PATTERN
insert_before () {
	filename=$1
	patterns=$2
	text="$3"
	size=$(cat $filename | wc -l)

	patched=$(pcregrep -Mine "${text}${pattern}" $filename | wc -l)
	if [ $patched -gt 0 ]; then echo "already patched, skipping..."; return; fi

 	match=$(pcregrep -Mine "$pattern" $filename)
  	msize=$(pcregrep -Mine "$pattern" $filename | wc -l)
  	start=$(echo $match | cut -d: -f1)

	sed "${start}i\\ 
${text}" $filename > /tmp/ppf.tmp
	mv /tmp/ppf.tmp $filename
}

reset_pf () {
	cp /etc/pf.conf.backup /etc/pf.conf
	return
}

#reset_pf
#clear;
pf=/etc/pf.conf

insert_after $pf "(table(\n|.)*pass.*\n)" "#test\\
ext_if=\"hn0\"\\
"
insert_after $pf "nat" "# /NAT\n"
insert_before $pf "table" "#REDIRECTS\\
#sdfs\\
#aqq\\
"
insert_before $pf "^" "# hey"