cURL: how to return 0 if status is 200?

Question

How can I return 0 when the response status is 200?

Right now I'm able to get the status, e.g. 200 with the following command:

curl -LI http://google.com -o /dev/null -w '%{http_code}\n' -s

But what I need to do is turn this 200 in a return 0.

How can I achieve this?

I tried the following command but it doesn't return:

if [$(curl -LI http://google.com -o /dev/null -w '%{http_code}\n' -s) == "200"]; then echo 0

Isn't the return code 0 if the command is successfult? Why not just use `$?` — msg, Sep 14 '18 at 00:58
The code you showed should not run due to syntax errors. Also see [How to use Shellcheck](https://github.com/koalaman/shellcheck), [How to debug a bash script?](https://unix.stackexchange.com/q/155551/56041) (U&L.SE), [How to debug a bash script?](https://stackoverflow.com/q/951336/608639) (SO), [How to debug bash script?](https://askubuntu.com/q/21136) (AskU), [Debugging Bash scripts](http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_02_03.html), etc. — jww, Sep 14 '18 at 01:40

score 20 · Answer 1 · answered Aug 09 '19 at 15:32

You can also use the -f parameter:

(HTTP) Fail silently (no output at all) on server errors. This is mostly done to better enable scripts etc to better deal with failed attempts.

So:

curl -f -LI http://google.com

Will return status 0 if the call was sucessful.

score 12 · Accepted Answer · answered Sep 14 '18 at 00:47

12

Looks like you need some spaces and a fi. This works for me:

if [ $(curl -LI http://google.com -o /dev/null -w '%{http_code}\n' -s) == "200" ]; then echo 0; fi

answered Sep 14 '18 at 00:47

Jack

5,801
1
15
20

score 4 · Answer 3 · answered Sep 19 '18 at 08:14

The most simple way is to check for curl's exit code.

$ curl --fail -LI http://google.com -o /dev/null -w '%{http_code}\n' -s > /dev/null
$ echo $?
0
$ curl --fail -LI http://g234234oogle.com -o /dev/null -w '%{http_code}\n' -s > /dev/null
$ echo $?
6

Please note that --fail is neccessary here (details in this answer). Also note as pointed out by Bob in the comments ^{(see footnote)} that in case of a non-200 success code this will still return 0.

If you don't want to use that for whatever reason, here's the other approach:

http_code=$(curl -LI http://google.com -o /dev/null -w '%{http_code}\n' -s)
if [ ${http_code} -eq 200 ]; then
    echo 0
fi

The reason your code isn't working is because you have to add spaces within the brackets.

_{(Copied from my answer on SuperUser where OP cross-posted the by now deleted question)}

score 0 · Answer 4 · answered Sep 14 '18 at 01:22

0

Another way is to use the boolean operator && :

[ $(curl -LI http://google.com -o /dev/null -w '%{http_code}\n' -s) == "200" ] && echo 0

The second command will be executed only if the first part is True.

answered Sep 14 '18 at 01:22

Gianluca Mereu

300
1
4

cURL: how to return 0 if status is 200?

4 Answers4