Condition shell comparison don't work

Question

data=$(wget -qO - https://blockchain.info/fr/q/addressbalance/$pk)
if [$data != 0]; then
    echo "Hello"
else
    echo "good bye"
fi

I have tried a lot of possibilities. I don't know how to work this.

I don't understand why this condition doesn't work.

wget -qO - https://blockchain.info/fr/q/addressbalance/$pk if [$? != 0]; then echo "Hello" else echo "good bye" fi

Result: 192005332305./btc.sh: ligne 6: [0 : commande introuvable good bye

BTW, http://shellcheck.net/ would have caught this for you automatically without getting humans involved. — Charles Duffy, Feb 22 '18 at 22:18

daddykom · Accepted Answer · 2018-02-22T21:09:16.893

1

Command does not return the errorcode, use $?

wget -qO - https://blockchain.info/fr/q/addressbalance/$pk
if [ $? != 0 ]; then
    echo "Hello"
else
    echo "good bye"
fi

You should have space inside the bracket.

Here my code for test, works perfekt:

wget -qO - $1 > test.txt
if [ $? != 0 ]; then
    echo "Hello"
else
    echo "good bye"
fi

edited Feb 22 '18 at 21:09

answered Feb 22 '18 at 19:40

daddykom

I have try this $? and it work. But i have always this error : ./mybtc.sh: ligne 6: [0 : commande introuvable – hn0x Feb 22 '18 at 19:53
Sorry, did not saw the second problem. – daddykom Feb 22 '18 at 20:18
I have all time the error ./mybtc.sh: ligne 6: [0 : commande introuvable Ligne 6 is if [$? != 0]; then – hn0x Feb 22 '18 at 20:29
the var pk is `pk=$(sed -n '1p' wall.txt)` – hn0x Feb 22 '18 at 20:33
it's my fault working now ! thx a lot – hn0x Feb 22 '18 at 20:35
No don't work, all time give hello. not problem i go research again solution ... – hn0x Feb 22 '18 at 20:49
So you file does not exists. Works perfekt here. – daddykom Feb 22 '18 at 21:07
In general, referring to `$?` when you don't need to is bad practice -- use `if ! wget -qO ...` if all you want to do is test for failure. – Charles Duffy Feb 22 '18 at 22:17

1 Answers1