") Syntax error Invalid arithmetic operator (error token is "

Question

I have commands in a bash script getting data from a source text file and then adding the value of a variable to it and using it in an if/else condition.

Source data file (db_count.ini) (Note: contains a space at the inside the double quotes):

db_ctdy_sr=" 7"

Script:

source db_count.ini

# Removing the whitespace on the stored data
n_db_sr=${db_ctdy_sr// /}

# Sum
c=0
b=7

echo "Value of db:"$n_db_sr

sm=$((n_db_sr + c))

echo "The value of db:"
echo "$sm" 
echo $sm 

if [ "$sm" = "$b" ]
then
   echo "Success."
else
   echo "Not."
fi

echo "Bye!"

But when I run the script it always me this

The value of db:7
") Syntax error Invalid arithmetic operator (error token is "
The value of:


Not.
Bye!

Any tips? Any suggestions?

Thanks!

Solution

Your script is working here. The only way to make it produce the same error you report is to make the variable db_ctdy_sr contain a new line:

Add a new line:

source db_count.ini
db_ctdy_sr=$' 7\r'

And then test the script:

$ ./so

Value of db:7
")syntax error: invalid arithmetic operator (error token is "
The value of db:
 //test if working
//test if working
Not.
Bye!

That could happen if the file db_count.ini contains DOS carriage return characters.

Execute:

$ sed -n l db_count.ini
db_ctdy_sr= 7\r$

(or similar) to see the \r in the file.

remove carriage returns by editing the file and removing the failing characters, or by changing this line:

n_db_sr=${db_ctdy_sr// /}

To:

n_db_sr=${db_ctdy_sr//[ $'\r'}]}

Or, more general to remove all control characters:

n_db_sr=${db_ctdy_sr//[ $'\001'-$'\037']}

To make sure the collating order will not modify the intended order of ascii values from 1 (octal 001) to 31 (octal 037), set the bash variable:

shopt -s globasciiranges

Available since bash version 4.3.

Comments

[Jeff Schaller]

I can only get close to your error when I mangle the db_ctdy_sr assignment, for example: db_ctdy_sr=" 7\"" -- can you confirm the exact syntax that db_count.ini is using?

[Edmhar]

@JeffSchaller, check my post again sir I had update some of the codes changing $a to $sm

[Edmhar]

@JeffSchaller , Inside the db_count.ini you can see a variable named db_ctdy_sr=" 7"

[dave_thompson_085]

CR is decimal 13 but octal $'\015' or hex $'\xD' -- and bash $' ' also supports more convenient \r.

[Admin]

@dave_thompson_085 Yes, you are right; thanks, included.