4 reasons for “curl no url specified” error – Code Examples

We get curl no url specified error due to reasons like we forgot to provide url or the command broke in the middle because of multi lines or a flag is added but we missed providing parameter to it.

Introduction

CURL is a utility used to transfer data from one system to another using protocols like GET, POST, PUT, DELETE etc. It is widely used among all the major programming languages. There are multiple flags which can be used to define the properties of request and response.

Why we get curl no url specified error?

“curl no url specified” error means that curl command is not able to recognize the url. It could be a possibility that you provided the url but yet got the error. This is because there is no defined position of url in curl command. Generally we put it in the end but it could change position based on parameters.

These are the 4 reasons for curl no url specified error –

1. Forgot to add url in command
2. Added url but there is a parameter without value.
3. Using wrong parameter case, upper and lower.
4. Broke command in multi lines without providing escape character \.

Solutions

In the above section we listed 4 reasons for the error. Let’s check the solution for all of them.

Solution 1: If forgot to add url in command

This is unlikely mistake but could happen. Sometimes our curl command gets too complex and we forget some essential parts of it. Check this code –

curl --request POST -H "Content-Type: application/json" -d "{}" --cookie "id=65" -u "username:password"

In this code we did a lot of things and forgot to add url. It will raise no url error of curl. To resolve the error, we need to add the url in this code –

curl --request POST -H "Content-Type: application/json" -d "{}" --cookie "id=65" -u "username:password" https://akashmittal.com

Solution 2: Added url but value for a parameter is missing

How missing value of a parameter can raise “curl no url” error? Actually, it can. Suppose you passed a --referer flag and url, then curl will consider that url as referer url. You need to have two urls in the command then. Check this code –

curl --referer https://akashmittal.com/?id=54

This command will raise no url specified in curl error. Because the url we added in curl will act as referer url. We need another url for sending request to, like this –

curl --referer https://akashmittal.com https://akashmittal.com/?id=54

Solution 3: Wrong parameter case, upper or lower

There are many parameters in curl which are different in properties but only differs in case like -o and -O, -x and -X, -y and -Y, -v and -V etc. If we use a wrong case then result will be unexpected. Sometimes it leads to no url specified error. Check this code –

curl -o https://akashmittal.com/ads.txt

In this command we passed -o flag. Our intention was to save ads.txt in our system but we end up getting error. This is because -o flag writes output to a provided file. What we need to use is, -O flag. This will write the output to ads.txt in local system. So correct code is –

curl -O https://akashmittal.com/ads.txt

You can find the downloaded output in the present working directory. Use ls to list all files and check if file is created –

$ ls
ads.txt

If the file is editable then you can use editors like nano or vim to open it.

Solution 4: Breaking curl command in multiline

If you want to write your command in multiline then you will need to end each line with escape character \. This works in linux. For windows try to write the whole command in single line.

This code will generate “curl no url specified” error –

curl --request POST 
-H "Content-Type: application/json" 
-d "{}" 
--cookie "id=65" 
-u "username:password" 
https://akashmittal.com
 

The above command will break in the first line only. Because there is no way for terminal to know if the command continues in the next line. To solve this issue, use escape character –

curl --request POST \
-H "Content-Type: application/json" \
-d "{}" \
--cookie "id=65" \
-u "username:password" \
https://akashmittal.com

Conclusion

Curl is an important tool which is used for data transfer among computers. This happens over the destination url. Since url is an important entity, we often get curl: no url specified error. In this article we saw 4 different reasons for this error and found their solutions.