Multi tool use

Sed remove character at beginning of string

I have the following script which inserts a "#" before a IP-address in a nginx config to act as a comment.

#!/bin/bash
hosts=( 84.19.155.71 84.19.155.72 )
for i in "${hosts[@]}"
do
CHECK=`grep $i nginx.conf`
if [[ ! "$CHECK" =~ ^#.*$ ]]
then
nc -zw 5 $i 5044
if [ "$?" != "0" ]
then
sed -i "/$i/s/^/#/" nginx.conf
else
sed -i 's/#*$i/$i/' nginx.conf
fi
fi
done


It works to insert the "#" at the beginning of the string but now I want to remove it if the exit code of the nc command is 0. I tried it with my else statement as shown above but to no avail. This is what the nginx.conf looks like:

nc

nginx.conf

user root;
worker_processes auto;
pid /run/nginx.pid;
load_module /usr/lib/nginx/modules/ngx_stream_module.so;


worker_rlimit_nofile 1000000;

events {
worker_connections 20000;
# multi_accept on;
}

stream {
log_format basic '$time_iso8601 $remote_addr '
'$protocol $status $bytes_sent $bytes_received '
'$session_time $upstream_addr '
'"$upstream_bytes_sent" "$upstream_bytes_received" "$upstream_connect_time"';

# Enable access_log statements for debugging
access_log /var/log/nginx/stream.log basic;

upstream syslog_udp {
#hash $remote_addr;
server 84.19.155.71:514 max_fails=2 fail_timeout=5s;
# server 84.19.155.72:514 max_fails=2 fail_timeout=5s;
}
server {
listen 514 udp;
proxy_pass syslog_udp;
proxy_responses 0;
#proxy_timeout 2s;
proxy_bind $remote_addr transparent;
#proxy_next_upstream_timeout 2s;
}
}


Can anyone help removing the "#" character from the IP-address?

2 Answers
2

First, only lines that do not begin with # are processed by the first if statement if [[ ! "$CHECK" =~ ^#.*$ ]]

if [[ ! "$CHECK" =~ ^#.*$ ]]

Adding # looks fine and for removing, you could try:

sed -i "s/^#*$i//" nginx.conf


if [[ ! "$CHECK" =~ ^#.*$ ]] this will take only lines which doesnt start with "#"
you may have to revisit that part which i will not discuss.

But here is the sed replace which might help you.

user@machine:$cat sample
server 84.19.155.71:514 max_fails=2 fail_timeout=5s;
#server 84.19.155.72:514 max_fails=2 fail_timeout=5s;

user@machine:$sed "s/^#(.*$i.*)/1/g" sample
server 84.19.155.71:514 max_fails=2 fail_timeout=5s;
server 84.19.155.72:514 max_fails=2 fail_timeout=5s;


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