Reading lines in a file and avoiding lines with # with Bash

Question

I tried this:

file=\"myfile\"
while read -r line
do
    [[ $line = \\#* ]] && continue
    \"address=\\$line\\127.0.0.1\"
done < \"$file\"
         


        

Answer 1

awk '{ if ($0 !~ /^#/){printf "address=/%s/127.0.0.1 \n",$0}}' <your_input_file>

Answer 2

You can filter with awk:

awk '!/^#/{print"address=/"$0"/127.0.0.1"}' file

Answer 3

[ "${line:0:1}" = "#" ] && continue

This takes the string, gets the substring at offset 0, length 1:

"${line:0:1}"

and checks if it is equal to #

= "#"

and continues looping if so

&& continue

http://www.tldp.org/LDP/abs/html/string-manipulation.html

Answer 4

Comment lines can and often do begin with whitespace. Here's a bash native regex solution that handles any preceeding whitespace;

while read line; do
  [[ "$line" =~ ^[[:space:]]*# ]] && continue
  ...work with valid line...
done

Answer 5

Maybe you can try

[[ "$line"~="#.*" ]] && continue

Check the ~ in operand!

Answer 6

It has 3 parts. Please read each to understand clearly

1. To remove # line ----- awk -F'#' '{print $1}' t.txt
2. To remove a blank line created by # ---- awk 'NF > 0'
3. To print in required format. ------awk '{print "address=/"$0"/127.0.0.1"}'

So Total Script Needed is,

**awk -F'#' '{print $1}' t.txt | awk 'NF > 0' | awk '{print "address=/"$0"/127.0.0.1"}'**

Output :

address=/domain1.com/127.0.0.1
address=/domain2.com/127.0.0.1
address=/domain3.com/127.0.0.1
address=/domain5.com/127.0.0.1