how to send integer as a parameter?

Question

I am not able to find why my code is not running. I am trying to send integers as the actual parameters to the add() function. As command substitution will substitutes the output of add() in the place of add 5 6.

#!/bin/bash

add () {
        echo `expr $1 + $2`
}

VAR= `add 5 6`
echo ${VAR:-"This is not defined"}

The only real reason to use `expr` is for regular-expression matching; prefer the arithmetic expression `$(( $1 + $2 ))` instead. — chepner, Oct 26 '18 at 15:24

score 1 · Answer 1 · answered Oct 25 '18 at 12:25

1

Remove the space after = in your VAR command.

VAR=`add 5 6`

answered Oct 25 '18 at 12:25

Mayank Porwal

33,470
8
37
58

yes it worked now, thanks. can you tell why does unix shows this type of behavior ? – vivek gupta Oct 25 '18 at 12:29
@vivekgupta This is the syntax Unix follows. You would need to re-search more to know why. – Mayank Porwal Oct 25 '18 at 12:33

score 1 · Accepted Answer · answered Oct 25 '18 at 12:30

1

There is a space after VAR=, you need to remove the space:

#!/bin/bash

add () {
        echo `expr $1 + $2`
}

VAR=`add 5 6`
echo ${VAR:-"This is not defined"}

Output is

https://www.tldp.org/LDP/abs/html/varassignment.html

answered Oct 25 '18 at 12:30

ScottBro

309
1
12

how to send integer as a parameter?

2 Answers2