Shell Programming and Scripting

Hi all,

Case 1 :

Code:

A=88^M
[ $A -eq 88 ] && echo "PASS"

Result:

Code:

PASS

Case 2:

Code:

A=88
[ $A -eq 88 ] && echo "PASS"

Result:

Code:

PASS

I would like to know why Case 1 and Case 2 got the same result? What make ^M ignored ?

Thanks in advance.

Enclose them with simple quote and test again

Thanks the quick reply.

Case 1 :
A=88^M
[ $A -eq '88' ] && echo "PASS"

Result:
PASS

Case 2:
A=88
[ $A -eq '88' ] && echo "PASS"

I have retest with single quote and got the same result.

As I am facing a problem that, the script work in some machine and not work in another, but the script is exactly the same. So, I would like to know any terminal setting will affect the test command when the string comparison with special character.

Other way around.... quotes around the variable, not the number

As well as on what is on the right side of the = sign

Code:

A='88^M'

[ "$A" ...

O ... Thanks ... But it got the Syntax error.

Using "==" rather than -eq will get the difference result. However, I would like to know the reason that what make the -eq comparison ignored special character.

Thanks again.

-eq is a numerical comparison. I get a syntax error for your first case on bash/cygwin, but it may be that your shell implementation is just ignoring any trailing characters which don't evaluate to a number.