CODEWITHSUNDEEP
bash
PatLas
PatLas

Reputation: 189

Bash error with subtraction

I've got some problem with substraction and I don't know why :( it's my code:

#!/bin/bash
w3m http://www.weather.com/weather/hourbyhour/graph/PLXX0027 > plik.txt
image= grep -o 'http.*' plik.txt
t= cat plik.txt |sed '105q;d' | grep -o '[0-9][0-9]'
a=32
temp=$((t-a))
echo $temp

I've received sth like:

name@name ~/Desktop $ sh p.sh
http://s.imwx.com/v.20120328.084252//img/wxicon/70/14.png
25
-32

but i wan to receive substraction of 25-32... (of course 25 depends of value in webpage) but why it don't want substract it?

Upvotes: 1

Views: 113

Answers (1)

fedorqui
fedorqui

Reputation: 290015

Try defining properly all variables, with $() surrounding them.

#!/bin/bash
w3m http://www.weather.com/weather/hourbyhour/graph/PLXX0027 > plik.txt
image=$(grep -o 'http.*' plik.txt)
t=$(cat plik.txt |sed '105q;d' | grep -o '[0-9][0-9]')
a=32
temp=$((t-a))
echo $temp

Upvotes: 2

Related Questions