Append line to /etc/hosts file with shell script

Question

I have a new Ubuntu 12.04 VPS. I am trying to write a setup script that completes an entire LAMP installation. Where I am having trouble is appending a line to the /etc/ho

Answer 1

If your in mac or you need sudo permission to this try this:

sudo -- sh -c -e "echo '192.34.0.03   subdomain.domain.com' >> /etc/hosts";

It will still ask you for password.

alternative way from @kainjow

echo '192.34.0.03 subdomain.domain.com' | sudo tee -a /etc/hosts

Answer 2

echo "127.0.0.1 localhost `hostname`">./temp_hosts
echo "192.241.xx.xx  venus.example.com">>./temp_hosts
cat /etc/hosts |tail -n +2 >>./temp_hosts
cat ./temp_hosts > /etc/hosts
rm ./temp_file

Answer 3

try this with root access.

 public void edithost() {
    sudo("echo " + "192.168.43.1     www.openrap.com openrap" + " >> /etc/hosts");
    sudo("echo " + "192.168.43.1  openrap.com openrap" + " >> /etc/hosts");
    sudo("echo " + "192.168.2.144  www.openrap.com openrap" + " >> /etc/hosts");
    sudo("echo " + "192.168.2.144  openrap.com openrap" + " >> /etc/hosts");
}

sudo for super user permission

public static void sudo(String... strings) {
    try {
        Process su = Runtime.getRuntime().exec("su");
        DataOutputStream outputStream = new DataOutputStream(su.getOutputStream());

        for (String s : strings) {
            outputStream.writeBytes(s + "\n");
            outputStream.flush();
        }

        outputStream.writeBytes("exit\n");
        outputStream.flush();
        try {
            su.waitFor();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        outputStream.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

this will append the lines to hosts in the android

Answer 4

I should point out that sed (the stream editor) is not actually intended for editing files, although it can be used to do that. (Standard sed doesn't have a built-in mechanism for writing to other than standard output.) A more appropriate tool would be ed.

The following ed script says "find the line containing the (admittedly sloppy) regular expression /127.0.0.1/ and append at the next line." (The lone period tells ed to stop appending.)

ed /etc/hosts <<-'EOF'
    /127.0.0.1/a
    192.241.xx.xx  venus.example.com
    .
    wq
EOF

That said, you can really just append this line to the end of your /etc/hosts file very trivially:

echo '192.241.xx.xx  venus.example.com' >> /etc/hosts

Answer 5

Insert/Update Entry

If you want to programmatically insert/update a hosts entry using bash, here's a script I wrote to do that:

#!/bin/bash

# insert/update hosts entry
ip_address="192.168.x.x"
host_name="my.hostname.example.com"
# find existing instances in the host file and save the line numbers
matches_in_hosts="$(grep -n $host_name /etc/hosts | cut -f1 -d:)"
host_entry="${ip_address} ${host_name}"

echo "Please enter your password if requested."

if [ ! -z "$matches_in_hosts" ]
then
    echo "Updating existing hosts entry."
    # iterate over the line numbers on which matches were found
    while read -r line_number; do
        # replace the text of each line with the desired host entry
        sudo sed -i '' "${line_number}s/.*/${host_entry} /" /etc/hosts
    done <<< "$matches_in_hosts"
else
    echo "Adding new hosts entry."
    echo "$host_entry" | sudo tee -a /etc/hosts > /dev/null
fi

The script is intended for use with OS X but would work on linux as well with minor tweaking.

Answer 6

you can use sed, like:

sed '/Venus/ a\  
192.241.xx.xx  venus.example.com venus' /etc/hosts