• Curl Make Post Request
• Curl Patch Request Body

When there is a security fix available for a particular software, we typically do a binary upgrade using the package management tools like yum or apt-get.

Curl patch vs post. What is the difference between PUT, POST and PATCH?, Difference between PUT, POST, GET, DELETE and PATCH IN HTTP Verbs: The most commonly used HTTP verbs POST, GET, PUT, DELETE Your command line should work. As you can see in the PATCH RFC5789, the HTTP request is similar what curl sends (use -trace-ascii to get to see the. Search WordPress.org for: Submit Toggle Menu. Showcase; Learn; Themes; Plugins; Mobile; Support. Five for the Future. Select the Network tab in devtools and tick the Preserve log checkbox (Persist Logs for firefox). Submit the form and locate the entry with method POST (right-click on any column header and make sure Method is checked). Right click the line with POST, and select Copy Copy as cURL. Chrome will copy all the request data in cURL syntax.

But, there might be situation where you have installed a software by compiling it from the source code.

In those situation, how do you apply the security fix to the software?

The answer is to download the security patch and apply it to the original source code and re-compile the software.

This tutorial explains how to create a patch file using diff, and apply it using patch command.

A patch file is a text file which contains the differences between two versions of the same file (or same source-tree). Patch file is created by using diff command.

1. Create a Patch File using diff

To understand this, let us create a small C program named hello.c

Now, copy the hello.c to hello_new.c

Edit the hello_new.c as shown below to make some small changes:

Finally, create the patch file using diff command as shown below:

The above command will create a patch file named “hello.patch”.

2. Apply Patch File using Patch Command

The “patch” command takes a patch file as input and apply the differences to one or more original file(s), producing patched versions.

Use the patch command as shown below to apply the hello.patch to the original hello.c source code.

The hello.patch file contains the name of the file to be patched. Once the file is patched, both hello.c and hello_new.c will have the content.

3. Create a Patch From a Source Tree

The above example was so simple that it works only with one file. We will see how to create and apply patch for a complete source tree by taking “openvpn” source code as example.

I’ve downloaded 2 version of openvpn, openvpn-2.3.2 and openvpn-2.3.4.

Now we will create the patch using the following command.

The above command will operate recursively and find the differences, and place those differences in the patch file.

4. Apply Patch File to a Source Code Tree

The following patch commands can be used to apply the patch to source tree.

Please note that we are executing the command from /usr/src/. The patch file contains all the filenames in absolute path format( from root ). So when we execute from /usr/src, without the “-p” option, it will not work properly.

-p3 tells the patch command to skip 3 leading slashes from the filenames present in the patch file. In our case, the filename in patch file is “/usr/src/openvpn-2.3.2/aclocal.m4”, since you have given “-p3”, 3 leading slashes, i.e. until /usr/src/ is ignored.

5. Take a Backup before Applying the Patch using -b

You can take a backup of the original file before applying the patch command using the -b option as shown below.

Now you will have a file name “hello.c.orig”, which is the backup of the original hello.c.

You can also use -V to decide the backup filename format as shown below. Now you will have a file name “hello.c.~1~”.

6. Validate the Patch without Applying (Dry-run Patch File)

You can dry run the patch command to see if you are getting any errors, without patching the file using –dry-run option as shown below.

You can see that hello.c is not modified at all.

7. Reverse a Patch that is Already Applied (Undo a Patch)

You can use the -R option to reverse a patch which is applied already.

You can notice from the filesize, that the patch, which is applied already is reversed when we used the -R option.

In this article, we’re going to discuss how to use curl to interact with RESTful APIs. curl is a command-line utility that can be used to send requests to an API.

API requests are made up of four different parts:

• The endpoint. This is the URL which we send requests to.
• The HTTP method. The action we want to perform. The most common methods are GETPOSTPUTDELETE and PATCH
• The headers. The headers which we want to send along with our request, e.g. authorization header.
• The body. The data we want to send to the api.

curl Syntax

The syntax for the curl command is:

The options we will cover in this post are:

• -X or --request - HTTP method to be used
• -i or --include - Include the response headers
• -d or --data - The data to be sent to the API
• -H or --header- Any additional headers to be sent

HTTP GET

The GET method is used to fetch a resource from a server. In curl, the GET method is the default method, so we don’t need to specify it.

Example:

GET With Query Parameters

We can also send query parameters along with the curl GET request.

Example:

HTTP POST

The POST method is used to create a resource on the server.

To send a curl POST request we use the option -X POST.

POST Form Data

Example:

By default, curl uses Content-Type: application/x-www-form-urlencoded as the Content-Type header, so we don’t need to specify it when sending form data.

POST JSON

To POST a JSON by curl we have to specify the Content-Type as application/json.

Example:

HTTP PUT

The PUT method is used to update or replace a resource on the server. It replaces all data of the specified resource with the supplied request data.

To send a curl PUT request we use the option -X PUT.

Example:

The above PUT request will replace our previously created post with “New post title” and “New post body”.

HTTP PATCH

The PATCH method is used to make partial updates to the resource on the server.

To send a curl PATCH request we use the option -X PATCH.

Example:

Notice how we are only sending the body with “Updated post content” as we are doing a partial update.

HTTP DELETE

Curl Make Post Request

The DELETE method is used to remove the specified resource from the server.

To send a curl DELETE request we use the option -X DELETE.

Authentication

Sometimes an API endpoint has restricted access and will only serve requests to authenticated and authorized users. For these requests, we have to provide an access token in the header of the request.

To send a curl header, we use: -H option.

The following request sends POST request with a bearer token in the header:

Conclusion

Curl Patch Request Body

In this post we learned how to send HTTP requests (GET, POST, PUT, PATCH and DELETE) to an API using curl commands.