bash scripting if statement, comparing decimal

Question

Kind of new to bash scripting and is having trouble with the below code. I am trying to compare the array number with the number you have input from the "read ans" the problem is mostly comparing decimal numbers

    BGpercent=(0 99 99.3 99.6 99.8 100)
    BGpoint=(0 1 2 3 4 5) 
    read ans
    for (( c=${#BGpercent[@]}; c>=0; c-- ))
    do  
       echo "${BGpercent[$c]}"
        if [ "${BGpercent[$c]}" <= "$ans"  ];  
        then
        result=${BGpoint[$c]}
        break
        fi
    done
    echo $result | bc -lstrong text

Error - ./testscript.sh: =: No such file or directory

chmod 750 testscript.sh then try to launch it. Also, add a shebang. — Jacek Trociński
– Jacek Trociński, Commented Nov 9, 2016 at 9:04

Arjun Mathew Dan · Accepted Answer · 2016-11-09 09:35:03Z

1

I guess the problem is in your if check (floating point comparison).

#!/bin/bash

    BGpercent=(0 99 99.3 99.6 99.8 100)
    BGpoint=(0 1 2 3 4 5)
    read ans
    for (( c=$[ ${#BGpercent[@]} - 1 ] ; c>=0; c-- ))
    do
        if (( $(echo "${BGpercent[$c]} <= $ans" |bc -l) ));
        then
        result=${BGpoint[$c]}
        break
        fi
    done

Also, the variable c value must be decremented in the beginning, else it will contain an invalid index value. I am not sure what you intent to do with the last line (echo $result | bc -lstrong text)

answered Nov 9, 2016 at 9:35

Arjun Mathew Dan

5,3281 gold badge18 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

thank you Over a year ago

Hi, thanks for the reply! now i am getting this error. syntax error on line 1, teletype

Arjun Mathew Dan Over a year ago

Did you change the c variable initialization in the for loop as well? See this link: unix.com/shell-programming-and-scripting/…

Thirupathi Thangavel Over a year ago

@A.M.D, did you change this? c=$[ ${#BGpercent[@]} - 1

Arjun Mathew Dan Over a year ago

@Thirupathi Thangavel : Yes i did

thank you · Accepted Answer · 2016-11-17 06:55:55Z

0

BGpercent=(0 99 99.3 99.6 99.8 100) BGpoint=(0 1 2 3 4 5)

echo " Write in your number:" read number

for (( c=${#BGpercent[@]}-1; c>-1; c-- )) do echo ${BGpercent[$c]} bool=echo "if (${BGpercent[$c]} <= ${number}) 1" | bc if [ "$bool"1 -eq 11 ] ; then result=${BGpoint[$c]} break fi

answered Nov 17, 2016 at 6:55

thank you

214 bronze badges

Collectives™ on Stack Overflow

bash scripting if statement, comparing decimal

2 Answers 2

4 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related