Make Me A Password

mmap

#!/usr/bin/env bash
#
# Copyright (C) 2012-2014 Jason A. Donenfeld <Jason@zx2c4.com>
# Copyright (C) 2015 SitePoint Pty Ltd.
#
# This file is licensed under the GPLv2+.
#
# Make Me A Password
#
# Generate a random password and copy it to the clipboard. Some code
# lifted from pass, "the standard unix password manager".
#

declare -r password="$(apg -n 1 -d -a 1 -m ${1-64} -x ${2-90})"
declare -ri clip_time=45
declare sleep_argv0
declare before
declare now
declare copy_cmd
declare copy_cmd_args
declare paste_cmd
declare paste_cmd_args

function check_cmd()
{
    if ! which "${1}" >/dev/null
    then
        echo "Error: '${1}' not found in path." 1>&2
        exit 1
    fi
}

if [[ "${OSTYPE}" == "darwin"* ]]
then
    copy_cmd="pbcopy"
    copy_cmd_args=""
    paste_cmd="pbpaste"
    paste_cmd_args=""
else
    copy_cmd="xclip"
    copy_cmd_args="-selection clipboard"
    paste_cmd="xclip"
    paste_cmd_args="-o -selection clipboard"
fi

check_cmd apg
check_cmd "${copy_cmd}"
check_cmd "${paste_cmd}"

# This base64 business is because bash cannot store binary data in a shell
# variable. Specifically, it cannot store nulls nor (non-trivally) store
# trailing new lines.
sleep_argv0="password store sleep on display $DISPLAY"
pkill -f "^$sleep_argv0" 2>/dev/null && sleep 0.5
before="$(${paste_cmd} ${paste_cmd_args} 2>/dev/null | base64)"
echo -n "${password}" | ${copy_cmd} ${copy_cmd_args} || \
    die "Error: Could not copy data to the clipboard"
(
    ( exec -a "$sleep_argv0" sleep "${clip_time}" )
    now="$(${paste_cmd} ${paste_cmd_args} | base64)"
    [[ $now != $(echo -n "${password}" | base64) ]] && before="$now"

    echo "$before" | base64 -d | ${copy_cmd} ${copy_cmd_args}
) 2>/dev/null & disown
echo -n "Generated password copied to clipboard. "
echo "Will clear in ${clip_time} seconds."