Add and remove time-sink websites to /etc/hosts with a simple command.

procras-filter

#!/usr/bin/env bash
## Adds time consuming websites to /etc/hosts and redirects them to localhost.
## Make sure you backup /etc/hosts and set its location in the env var.

BLOCKED_SITES=("facebook.com" "login.facebook.com" "www.facebook.com" "twitter.com" "news.ycombinator.com" "www.nytimes.com")
BACKUP_HOSTS="$HOME/local/var/hosts.bak"
DEST_HOSTS="/etc/hosts"

function print_help {
    echo "Usage: $(basename $0) [options]"
    echo "Poor man's procrastination filter. Use $DEST_HOSTS to block website access."
    echo "  -h    Show this usage guide."
    echo "  -B    Block sites by adding them to $DEST_HOSTS."
    echo "  -U    Unblock sites by restoring $DEST_HOSTS."
}

function block_sites {
    if [ -f "$BACKUP_HOSTS" ]; then
        echo -e "\n#blocked sites added by procras-filter" | sudo tee -a "$DEST_HOSTS"
        for site in "${BLOCKED_SITES[@]}"; do
            echo "127.0.0.1 $site" | sudo tee -a "$DEST_HOSTS"
        done
        exit 0
    else
        echo "Error: Not writing to $DEST_HOSTS without backup file: $BACKUP_HOSTS"
        exit 1
    fi
}

function unblock_sites {
    if [ -f "$BACKUP_HOSTS" ]; then
        echo "  Restoring $DEST_HOSTS, requires root privileges..."
        sudo cp "$BACKUP_HOSTS" "$DEST_HOSTS"
        exit 0
    else
        echo "Error: Unable to find backup hosts file: $BACKUP_HOSTS"
        exit 1
    fi
}

#parse args
while getopts "BUh" option; do
    case "$option" in
        B) block_sites;;
        U) unblock_sites;;
        h) print_help; exit 0;;
        \?) print_help; exit 0;;
    esac
done

#no cammand-line args...
print_help
exit 1