#!/bin/bash
# 'bc'¸¦ 'here document'¿Í °°ÀÌ ¾´ °ÍÀ» ¸í·É¾î ġȯÀ» ½á¼­ ½ÇÇà.


var1=`bc << EOF
18.33 * 19.78
EOF
`
echo $var1       # 362.56


#  $( ... ) Ç¥±â¹ýµµ ¿ª½Ã µË´Ï´Ù.
v1=23.53
v2=17.881
v3=83.501
v4=171.63

var2=$(bc << EOF
scale = 4
a = ( $v1 + $v2 )
b = ( $v3 * $v4 )
a * b + 15.35
EOF
)
echo $var2       # 593487.8452


var3=$(bc -l << EOF
scale = 9
s ( 1.7 )
EOF
)
# 1.7 ¶óµð¾ÈÀÇ »çÀΰªÀ» ¸®ÅÏ.
# "-l" ¿É¼ÇÀº 'bc'ÀÇ ¼öÇÐ ¶óÀ̺귯¸®¸¦ È£ÃâÇÕ´Ï´Ù.
echo $var3       # .991664810


# ÀÌÁ¦, ÇÔ¼ö¿¡¼­ ÇØ º¸ÁÒ...
hyp=             # Àü¿ª º¯¼ö ¼±¾ð.
hypotenuse ()    # Á¤»ï°¢ÇüÀÇ ºøº¯À» °è»ê.
{
hyp=$(bc -l << EOF
scale = 9
sqrt ( $1 * $1 + $2 * $2 )
EOF
)
# ºÒÇàÇÏ°Ôµµ, Bash ÇÔ¼ö¿¡¼­´Â ºÎµ¿Çü °ªÀ» ¸®ÅÏÇÒ ¼ö ¾ø½À´Ï´Ù.
}

hypotenuse 3.68 7.31
echo "hypotenuse = $hyp"    # 8.184039344


exit 0