#!/bin/bash

# ´ë»ó ÆÄÀÏ¿¡¼­ ÁÖ¾îÁø ¿­À» ´Ù ´õÇϱâ.

ARGS=2
E_WRONGARGS=65

if [ $# -ne "$ARGS" ] # ¸í·É¾îÁÙ ÀÎÀÚ ¼ö°¡ Àû´çÇÑÁö È®ÀÎ.
then
   echo "»ç¿ë¹ý: `basename $0` filename column-number"
   exit $E_WRONGARGS
fi

filename=$1
column_number=$2

# ½© º¯¼ö¸¦ awk ¿¡°Ô ³Ñ±â´Â °ÍÀº ¾à°£ ±î´Ù·Ó½À´Ï´Ù.
# ´õ ÀÚ¼¼ÇÑ °ÍÀº awk ¹®¼­¸¦ Âü°íÇϼ¼¿ä.

# ¿©·¯ÁÙÂ¥¸® awk ½ºÅ©¸³Æ®´Â    awk ' ..... '   ó·³ ºÎ¸£¸é µË´Ï´Ù.


# awk ½ºÅ©¸³Æ® ½ÃÀÛ.
# -----------------------------
awk '

{ total += $'"${column_number}"'
}
END {
     print total
}     

' "$filename"
# -----------------------------
# awk ½ºÅ©¸³Æ® ³¡.


#   ½© ½ºÅ©¸³Æ®¿¡ ³»ÀåµÈ awk ½ºÅ©¸³Æ®¿¡°Ô ½© º¯¼ö¸¦ ³Ñ±â´Â °ÍÀº 
#   ¾ÈÀüÇÏÁö ¾ÊÀ» ¼ö°¡ Àֱ⠶§¹®¿¡, Stephane Chazelas °¡ ´ÙÀ½°ú °°Àº ´ë¾ÈÀ» 
#   Á¦¾ÈÇØ ÁÖ¾ú½À´Ï´Ù:
#   ---------------------------------------
#   awk -v column_number="$column_number" '
#   { total += $column_number
#   }
#   END {
#       print total
#   }' "$filename"
#   ---------------------------------------


exit 0