Question

Can anyone tell me what I’m doing wrong here?

#!/bin/sh

if [ $# = 0 ]
then
    echo "Usage: $0 <filename>"
    exit 1
fi

sum=0
count=0

while [ $0 != 0 ]
do
        sum="$sum"+"$2"
        count="$count"+ 1

done
if [ "$count" != 0 ]
then
        avg="$sum"/"$count"
        printf "Sum= $sum \n Count= $count  \n Avg= $avg"
        exit 0
else
        printf "Sum= $sum \n Count= $count  \n Avg= undefined"
        exit 0
fi
exit 1

Here’s the output when I try to test the code:

./average

sum: =: No such file or directory
sum: 0: No such file or directory
./average: 11: count: not found
[: 18: !=0: unexpected operator
./average: 25: Syntax error: Unterminated quoted string

Basically if I had a file that looked something like this:

FirstPerson 23 

SecondPerson 36

ThirdPerson 22

I want to be able to read that into my program and have it output:

Sum = FirstPerson+SecondPerson+ThirdPerson

Count = NumberofPeople

Average = Sum/Count

Answer 1

the code below works, you can probably optimize it if you want (or use awk, perl, etc):

#!/bin/bash

if [ $# -ne 1 ]; then
        echo "Usage: \"$0\" <filename>"
        exit
fi

if [ ! -f $1 ]; then
        echo "$1 file not found."
        echo "Usage: $0 <filename>"
        exit
fi

sum=0
count=0
arq=$1

while read line
do
        num=`echo ${line#* }`
        sum=`expr $sum + $num`
        count=`expr $count + 1`
done < "$arq"

if [ "$count" != 0 ]
then
        avg=`expr $sum / $count`
        printf "Sum= \"$sum\" \n Count= \"$count\"  \n Avg= \"$avg\""
        exit 0
else
        printf "Sum= \"$sum\" \n Count= \"$count\"  \n Avg= undefined"
        exit 0
fi