I am unable to type cast string to integer in csh

Question

I want to fetch out '-0.5' from the file example.txt and add 1 to it.

Although I am able to fetch out '-0.5'. but I am unable to add 1 to it, maybe because -0.5 is considered as a string and not a integer.

Code:

#!/bin/csh
set x = `grep Name example.txt | cut -d "|" | -f 5`
echo $x
set y = `expr $x + 1`
echo $y

Obtained Result:

-0.5    
expr: non-numeric argument

Expected Result:

-0.5
0.5

How do I type cast -0.5 to integer?

Answer 1

csh doesn't have types, and everything is a string.

The problem is that expr only accepts integers: that is, whole numbers. The same applies to csh's built-in @ syntax.

It's usually better to use bc or dc for this:

% echo 0.5 + 1 | bc
1.5

% echo 0.5 1 + p | dc
1.5

So in your example:

#!/bin/csh
set x = `grep Name example.txt | cut -d "|" | -f 5`
set y = `echo "$x + 1" | bc`
echo $y