On performing SHELL scripting - facing Syntax error: "(" unexpected : "Faced with several other try with shell scripting with function definition"

வினா
1

Screenshot from 2023-11-13 11-07-40
Screenshot from 2023-11-13 11-07-40786×533 46.4 KB

pract3.sh: 1: Syntax error: “(” unexpected

For all below program facing this - common error while getting started refreshing shell programming:( Any reason or mis-leaded executions - please confirm)
==========For below line of code on pract3.sh=======================

function  user_input()
{
        read -p "Please enter cost center" costcenter
}

=============pract2.sh==========
ash

function get_salestax()
{
        if test "$1" = ""
        then
                echo "You must supply a full expense amopunt."
                return
        else
                echo "Full expense amount:" $1
                nontax_amount=`echo "$1/1/15" | bc`
                tax_amount=`echo "$1-$nontax_amount" | bc`
                echo "Non tax amount:"$nontax_amount
                echo "Tax amount:" $tax_amount
                return $tax_amount

        fi
        echo "Operation completed successfully!"
}

====================================================

2

மேலே கொடுக்கப்பட்டுள்ள தகவல்கள் சரியாக புரியவில்லை. ctrl-alt-t கொடுத்து டெர்மினலை துவக்கவும். பின் எந்த ஷெல்ஸ்கிரிப்டில் பிழை வருகின்றதோ அந்த ஷெல்ஸ்கிரிப்டை இயக்கவும். சிக்கல் வந்தபில் டெர்மினல் திரையை திரைப்பதிவு எடுக்கவும். பின் அதை இங்கே பகிரவும்.

4

இந்த சிக்கல் தொடர்கின்றதா என்று கூறவும்.

5

17000524380937149276860210458929
170005243809371492768602104589291920×2560 408 KB

சிக்கல் தொடர்கிறது.

6
  1. இதை இயக்கினால் என்ன வருகின்றது?
  2. என்ன வர வேண்டும் என்று எதிர்பார்கின்றீர்கள்?
7

After executing, I am expecting to execute without error and like to get an input after execution of above code. I never tried functions with shell, while experimenting with functions got this problem.

With an another instance, seen different problem with execution on shell scripting.
Error: pract4.sh: 8: Bad substitution ==> Was observed.
Solution found: When I try to execute from $PS1 ==> Worked ( Attached the observed copy)

Since, shell scripting - I have worked on basic- was advancing with experimenting with functions() ==> Seen persistent problems - That’s why like to ask for clarifications:

image
image1227×367 109 KB

8

can you sent the program inside the pract4.sh file

9 
#!/bin/bash
find_average() {
sum=0
i=1
len=$#
x=$((len + 1))
while [ $i -lt $x ]
do
arg=${!i}
sum=$((sum + arg))
i=$((i + 1 ))
done
avg=$((sum / len))
return $avg
}

find_average 10 20 30 40
echo $?
10

After executing, I am expecting to execute without error and like to get an input after execution of above code. I never tried functions with shell, while experimenting with functions got this problem.

ஒவ்வோரு ஷெல்ஸ்க்ரிப்டாக செல்வோம். pract3.sh ஐ இயக்கியவுடன் அந்த டெர்மினலை திரைப்பதிவு எடுத்து இங்கே பகிரவும்.

11

In this code arg = ${!i} is not working to get value from find_average 10 20 30 40.

use this code, I use for loop and get the output of this statement

find_average(){ 
  len=$#
  sum=0
  for x in "$@"
  do
     sum=$((sum + x))
  done
  avg=$((sum/len))
  return $avg
}

find_average 10 20 30 40
echo "$?"
12

while perform ${!i} this, we need to give permission for that file.
Give permission then use execute then the file

chmod u+x filename

then run

./filename
13

My LINUX system is using bash as default SHELL,
so, on executing with bash <script.sh> ==> got properly executed.

box@box-virtual-machine:~/shell_prog$ sh pract4.sh
pract4.sh: 9: Bad substitution
box@box-virtual-machine:~/shell_prog$ bas
base32 base64 basename basenc bash bashbug
box@box-virtual-machine:~/shell_prog$ bash pract4.sh
25
box@box-virtual-machine:~/shell_prog$

Thanks kalai and mohan for responding :wave:

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