#!/bin/bash
# max2.sh: ¾ÆÁÖ Å« µÎ Á¤¼öÁß Å« ¼ö ±¸Çϱâ.

# ÀÌ ½ºÅ©¸³Æ®´Â ¾Õ¿¡¼­ ¼Ò°³Çß´ø "max.sh" ¿¹Á¦¸¦
# Å« Á¤¼ö¿¡ ´ëÇؼ­ µ¿ÀÛÇϵµ·Ï ¼öÁ¤ÇÑ °ÍÀÔ´Ï´Ù.

EQUAL=0             # µÎ ¸Å°³º¯¼ö°¡ °°À» °æ¿ìÀÇ ¸®ÅÏ °ª.
MAXRETVAL=256       # ÇÔ¼ö°¡ ¸®ÅÏÇÒ ¼ö ÀÖ´Â ÃÖ´ë ¾ç¼ö.
E_PARAM_ERR=-99999  # ¸Å°³º¯¼ö ¿¡·¯.
E_NPARAM_ERR=99999  # "ÀϹÝÈ­µÈ"(Normalized) ¸Å°³º¯¼ö ¿¡·¯.

max2 ()             # µÎ ¼ýÀÚÁß Å« ¼ö¸¦ ¸®ÅÏ.
{
if [ -z "$2" ]
then
  return $E_PARAM_ERR
fi

if [ "$1" -eq "$2" ]
then
  return $EQUAL
else
  if [ "$1" -gt "$2" ]
  then
    retval=$1
  else
    retval=$2
  fi
fi

# -------------------------------------------------------------- #
# ¿©±â°¡ Å« Á¤¼ö¸¦ ¸®ÅÏÇÒ ¼ö ÀÖ°Ô ÇØ ÁÖ´Â ºÎºÐÀÔ´Ï´Ù.
if [ "$retval" -gt "$MAXRETVAL" ]    # ¹üÀ§¸¦ ³Ñ´Â ¼ö¶ó¸é,
then                                 
  let "retval = (( 0 - $retval ))"   # À½¼ö·Î Á¶ÀýÇØ ÁÝ´Ï´Ù.
  # (( 0 - $VALUE )) °¡ VALUE ÀÇ ºÎÈ£¸¦ ¹Ù²ãÁÝ´Ï´Ù.
fi
# ´ÙÇེ·´°Ôµµ, Å« *À½¼ö* ¸®ÅÏÀº °¡´ÉÇÕ´Ï´Ù.
# -------------------------------------------------------------- #

return $retval
}

max2 33001 33997
return_val=$?

# -------------------------------------------------------------------------- #
if [ "$return_val" -lt 0 ]                  # "Á¶ÀýµÈ" À½¼ö¶ó¸é,
then                                       
  let "return_val = (( 0 - $return_val ))"  # ¾ç¼ö·Î º¯È¯.
fi                                          # $return_valÀÇ "Àý´ë°ª".
# -------------------------------------------------------------------------- #


if [ "$return_val" -eq "$E_NPARAM_ERR" ]
then                   # ¸Å°³º¯¼ö ¿¡·¯ "Ç÷¡±×"µµ ºÎÈ£°¡ ¹Ù²ò´Ï´Ù.
  echo "¿¡·¯: ¸Å°³º¯¼ö°¡ ¸ðÀÚ¶ø´Ï´Ù."
elif [ "$return_val" -eq "$EQUAL" ]
  then
    echo "µÎ ¼ýÀÚ°¡ °°½À´Ï´Ù."
else
    echo "µÎ ¼ýÀÚÁß Å« ¼ö´Â $return_val ÀÔ´Ï´Ù."
fi  
  
exit 0