Helper script to check if connected to internet

utils/am-i-online.sh

@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+
+# A quick utility for checking if you're online
+# Checks interfaces, gateway, DNS, conntectivity
+# Licensed under MIT, (C) Alicia Sykes 2022
+
+# Colors and re-used string components
+pre_general='\033[1;96m'
+pre_success='  \033[1;92m✔'
+pre_failure='  \033[1;91m✗'
+post_string='\x1b[0m'
+
+# Checks if DNS gateway is online
+function aio_check-dns() {
+  : >/dev/tcp/1.1.1.1/53 > /dev/null && \
+  echo -e "${pre_success} DNS Online${post_string}" || \
+  echo -e "${pre_failure} DNS Offline${post_string}"
+}
+
+# Checks if can ping default getway
+function aio_ping-gateway() { 
+  ping -q -w 1 -c 1 `ip r | grep default | cut -d ' ' -f 3` > /dev/null && \
+  echo -e "${pre_success} Gateway Availible${post_string}" || \
+  echo -e "${pre_failure} Gateway Unavailible${post_string}"
+}
+
+# Checks if can curl a URL
+function aio_check-url() {
+  INTERNET_URL="${INTERNET_URL:-$1}"
+    if [ -z "$(curl -Is $INTERNET_URL | head -n 1 2>&1 )" ]
+    then
+        echo -e "${pre_failure} Domains Unaccessible${post_string}"
+    else
+        echo -e "${pre_success} Domains Accessible${post_string}"
+    fi
+}
+
+# Checks there are network interfaces
+function aio_check-interfaces() {
+  for interface in $(ls /sys/class/net/ | grep -v lo); do
+    if [[ $(cat /sys/class/net/$interface/carrier) = 1 ]]; then OnLine=1; fi
+  done
+  if ! [ $OnLine ]; then
+    echo -e "${pre_failure} Interfaces not Configured${post_string}"
+  else
+    echo -e "${pre_success} Interfaces Configured${post_string}" > /dev/stderr
+  fi
+}
+
+# Shows help menu
+function aio_help() {
+  echo -e "${pre_general}Utility for checking connectivity status${post_string}"
+  echo -e "\e[0;96mUsage:${post_string}"
+  echo -e "  \e[0;96m$ online${post_string}"
+}
+
+# Runs everything, prints output
+function aio_start() {
+  if [[ $@ == *"--help"* ]]; then
+    aio_help
+    return
+  fi;
+  line="${pre_general}─────────────────────────${post_string}"
+  echo -e ${line}
+  echo -e "${pre_general}📶 Checking connection...${post_string}"
+  echo -e ${line}
+  aio_check-dns
+  aio_ping-gateway
+  aio_check-url 'https://duck.com'
+  aio_check-interfaces
+  echo -e ${line}
+}
+
+# Determine if file is being run directly or sourced
+([[ -n $ZSH_EVAL_CONTEXT && $ZSH_EVAL_CONTEXT =~ :file$ ]] || 
+  [[ -n $KSH_VERSION && $(cd "$(dirname -- "$0")" &&
+    printf '%s' "${PWD%/}/")$(basename -- "$0") != "${.sh.file}" ]] || 
+  [[ -n $BASH_VERSION ]] && (return 0 2>/dev/null)) && sourced=1 || sourced=0
+
+# If script being called directly run immediatley, otherwise register aliases
+if [ $sourced -eq 0 ]; then
+  aio_start $@
+else
+  alias amionline=aio_start $@
+  alias online=aio_start $@
+  alias aio=aio_start $@
+fi