[SOLVED] math programming help in shell

sniper8752 · 10-15-2012, 12:33 PM

i am trying to do some math for a program, and i am getting an error. here is my code:
let perimeter=2*$l+2*$w

error:
rectangle: line 6: let: perimeter=2*: syntax error: operand expected (error token is "*")

Habitual · 10-15-2012, 12:41 PM

show us the entire script please.
[code][/code] tags Please.
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suicidaleggroll · 10-15-2012, 12:41 PM

The shell is not very good at doing math directly, but you can use other programs for this, such as bc.

Code:

perimeter=$(echo "2*$l+2*$w" | bc -l)

JaseP · 10-15-2012, 01:07 PM

Regular expressions ...

See;
http://www.freeos.com/guides/lsst/ch02sec07.html

You have to use escape characters to preserve mathematical functions...