proxy.sh - Proxy Auto-Configuration Utility

README.md

proxy.sh - Proxy Auto-Configuration Utility

Usage

Add below commands to ~/.bashrc.

. $SOMEWHERE/proxy.sh # [auto|fromsystem|pac <URL>|wpad]

proxy.sh

#!/usr/bin/env bash
#
# Proxy Auto-Configuration Utility
# Copyright 2020 (c) Koichi OKADA. All rights reserved.
# This script is distributed under the MIT license.
#

function proxy_GetSystemWebProxy.GetProxy () # [-v <varname>] [<URL=https://google.com/>]
#   Returns a proxy configured with the Internet Explorer.
# Arguments:
#   <URL> : The target URL to be checked if it requires a proxy.
# Optins:
#   -v <varname> : Return result to variable instead of stdout.
# Returns:
#   Return proxy if URL requires a proxy.
#   Otherwise, return an empty string.
# Reference:
#   * Docs / .NET / .NET API / browser / System.Net / WebRequest / Methods / GetSystemWebProxy
#     https://docs.microsoft.com/en-us/dotnet/api/system.net.webrequest.getsystemwebproxy
{
  local powershell; read powershell < <(type -p powershell.exe pwsh.exe powershell pwsh); [ -z "$powershell" ] && return 1
  local URL; [ $# = 1 -o $# = 3 ] && URL="${@: -1}"; URL="${URL:-https://google.com/}"
  [ $# = 2 -o $# = 3 ] && { [ "$2" = "proxy" ] && : || local -n proxy="$2"; } || local proxy
  read proxy < <("$powershell" -C '&{[System.Net.WebRequest]::GetSystemWebProxy().GetProxy($Args[0]).AbsoluteUri|sls -not $Args[0]|Write-Host -n}' "$URL")
  [ $# = 2 -o $# = 3 ] && return
  [ $# = 0 -o $# = 1 ] && { echo "$proxy"; return; }
  return 1
}

function proxy_fromsystem ()
#   Set proxy from system settings.
{
  local hash; read -d " " hash < <(ipconfig.exe |& md5sum -b)
  local cache="/tmp/.proxy_fromsystem.$hash"
  local last; read last < <(stat -c %Y "$cache" 2>/dev/null)
  local now; printf -v now "%(%s)T"
  local proxy

  [ -n "$OPT_PROXY_FORCE_REFRESH" ] && last=0
  if (( (now - ${last:-0}) < ${OPT_PROXY_REFRESH_INTERVAL:-86400} )); then
    read proxy < "$cache"
  else
    proxy_GetSystemWebProxy.GetProxy -v proxy || return
    echo "$proxy" > "$cache"
  fi
  [ -n "$proxy" ] && proxy_set "$proxy" && return
  proxy_unset
}

function proxy_auto ()
#   Auto set proxy
{
  proxy_fromsystem || proxy_wpad
}

function proxy_update_with_pac ()
#   Update proxy with PAC
# Environments:
#   $PROXY_PAC : An URL of the Proxy Auto-Configuration file.
{
  local hash; read -d " " hash < <(ipconfig.exe |& md5sum -b)
  local cache="/tmp/.wpad.sh.$hash"
  local last; read last < <(stat -c %Y "$cache" 2>/dev/null)
  local now; printf -v now "%(%s)T"
  local proxy
  
  [ -n "$OPT_PROXY_FORCE_REFRESH" ] && last=0
  if (( (now - ${last:-0}) < ${OPT_PROXY_REFRESH_INTERVAL:-86400} )); then
    read proxy < "$cache"
  else
    read proxy < <(
      wget --no-proxy -qO - "${PROXY_PAC:=wpad/wpad.dat}" \
      | grep PROXY \
      | sed -E 's@^.*"\s*PROXY\s*([^"]*)\s*".*$@http://\1@g')
    echo "$proxy" > "$cache"
  fi
  [ -n "$proxy" ] && proxy_set "$proxy"
}

function proxy_refresh ()
#   Refresh Proxy
# See:
#   proxy_update
{
  OPT_PROXY_FORCE_REFRESH=1 proxy_auto
}

function proxy_pac () # <url>
#   Update Proxy with PAC(Proxy Auto-Configuration)
{
  PROXY_PAC="$1"
  proxy_update_with_pac
}

function proxy_wpad ()
#   Update Proxy with WPAD(Web Proxy Auto Discovery).
{
  proxy_pac
}

function proxy_set () # <proxy>
#   Set ftp, http, https, no proxy
# Arguments:
#   proxy : Proxy schema and host and port with "schema://host:port"
{
  #local ips; printf -v ips ",%s" 192.168.{0..1}.{1..254}
  export no_proxy="localhost,127.0.0.1,localnet$ips"
  export {ftp,http,https}_proxy="$1"
}

function proxy_unset ()
#   Set ftp, http, https proxy
# Arguments:
#   proxy : Proxy schema and host and port with "schema://host:port"
{
  unset {ftp,http,https,no}_proxy
}

function proxy_export ()
#   Export proxy settings
{
  declare -p {ftp,http,https,no}_proxy 2>/dev/null
}

function proxy () # <subcommand>
#   Proxy Manager
{
  if type "${FUNCNAME}_${1:-auto}" >&/dev/null; then
    "${FUNCNAME}_${1:-auto}" "${@:2}"
  else
    gawk '
      /^function/,/^{/ {
        if      (match($0,/^function[[:space:]]+([^[:space:]]*)[[:space:]]*\(\)[[:space:]]*(#(.*))?/,m)) {print "Usage: "m[1]m[3];}
        else if (match($0,/^#[[:space:]]?/))                                                             {print substr($0,RSTART+RLENGTH);}
        else                                                                                             {print "";}
      }
    ' "$BASH_SOURCE"
    echo "Error: Unknown subcommand: $1"
    return 1
  fi
}

if [ "$0" = "$BASH_SOURCE" ]; then
  SCRIPT_PATH="$0"
  SCRIPT_DIR="${SCRIPT_PATH%/*}"
  SCRIPT_FILE="${SCRIPT_PATH##*/}"
  SCRIPT_NAME="${SCRIPT_FILE%.*}"
  "$SCRIPT_NAME" "$@"
else
  proxy "$@"
fi