#!/bin/bash
# setdate--Friendly frontend to the date command
# Date wants: [[[[[cc]yy]mm]dd]hh]mm[.ss]

# To make things user-friendly, this function prompts for a specific date
#   value, displaying the default in [] based on the current date and time.

source ../1/library.sh # source our library of bash functions to get echon()

proc askvalue
{
  # $1 = field name, $2 = default value, $3 = max value,
  # $4 = required char/digit length

  echon "$1 [$2] : "
  read answer
  if test $(answer:=$2) -gt $3  {
    echo "$0: $1 $answer is invalid"; exit 0
  } elif test "$shExpr(' $(echo $answer | wc -c) - 1 ')" -lt $4  {
    echo "$0: $1 $answer is too short: please specify $4 digits"; exit 0
  }
  eval $1=$answer   # Reload the given variable with the specified value.
}

eval $[date "+nyear=%Y nmon=%m nday=%d nhr=%H nmin=%M]

askvalue year $nyear 3000 4
askvalue month $nmon 12 2
askvalue day $nday 31 2
askvalue hour $nhr 24 2
askvalue minute $nmin 59 2

#squished="$year$month$day$hour$minute"

# Or, if you're running a Linux system:
setglobal squished = ""$month$day$hour$minute$year""
# Yes, they use different formats, Linux and OS X/BSD systems. Helpful, eh?

echo "Setting date to $squished. You might need to enter your sudo password:"
sudo date $squished

exit 0