awk help

[Polytropon]

Allow me a few comments regarding sh -> awk for reformatting
your input data.

On Sun, 10 Sep 2017 09:32:02 -0400, Ernie Luzar wrote:
>      # Locate and replace carriage return with blank.
>      line=`echo -n "${line}" | tr '\r' ' '`

Drop the ^Ms in a pipe step ... | tr -d '\r' | ...



>      # Locate and replace tab with blank.
>      line=`echo -n "${line}" | tr '\t' ' '`

No need, awk defaults to tab(s) and/or space(s) as field
separators, and you can easily access the fields with $1,
$2, $3 and so on.



>      # Drop blank lines.
>      blank_line=`echo -n $line | cut -c 1-1`
>      if [ "$blank_line" = " " ]; then
>        continue
>      fi

Just add a rule (length > 0) infront of your { ... awk
statements for each line }.



>      # Drop lines with localhost in it.
>      localhost=`echo -n $line | cut -w -f 2`
>      if [ "$localhost" = "localhost" ]; then
>        continue
>      fi

Expand the rule like (length > 0 && $2 != "localhost") { ... },
in case "localhost" is the exact text; if you want to use a
reges, use $2 != /localhost/ instead.



>      # Drop line with # in cloumn 1 as a comment.
>      comment1=`echo -n $line | cut -c 1-1`
>       if [ "$comment1" = "#" ]; then
>        continue
>      fi

Add another rule as reges !/^#/ && ( ... as above ... ) { ... }
to filter those. Or, also possible, use ... | grep -v "^#" | ...
infront of awk.



>      # Drop line with word Malvertising starting in cloumn 1
>      comment1=`echo -n $line | cut -w -f 1`
>      if [ "$comment1" = "Malvertising" ]; then
>        continue
>      fi

See above.



>      # Out put record.
>      ip=`echo -n $line | cut -w -f 1`
>      $trace_on echo "ip = ${ip}"
>      if [ "$ip" = "127.0.0.1" -o "$ip" = "0.0.0.0" ]; then
>        domain_name=`echo -n $line | cut -w -f 2`
>        echo "local-zone: \"${domain_name}\" always_nxdomain" >> $host_out
>        continue
>      else
>        domain_name=`echo -n $line | cut -w -f 1`
>        echo "local-zone: \"${domain_name}\" always_nxdomain" >> $host_out
>      fi

Construct an output statement as desired. Use variables instead
of $1, $2, $3 if the whole things gets too complex, for example
like this (not tested, just for illustration):

#!/bin/sh

cat input.txt | tr -d '\r' | awk '
!/^#/ && (length > 0) {
	ip = $1
	host = $2

	if (!(host == "localhost" || ip == "127.0.0.1" || ip == "0.0.0.0"))
		printf("local-zone: \"%s\" always_nxdomain\n", ip)
	else
		printf("local-zone: \"%s\" always_nxdomain\n", host)
}' > output.txt

That should be basically what you need. You now just have to
combine the moving parts correctly. :-)





-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...