Quick Tip: Sending Newlines with cURL

Tue, 03 May 2016 22:12:28 +0000

Yikes, this took far too long to figure out!

I have a service which takes plain text multi-line input and outputs an object for each line, something like this:

Input

Line 1
Line 2
Line 3

Output

[
{line: "Line 1"},
{line: "Line 2"},
{line: "Line 3"}
]

There’s a bit more to it than that, but that’s the gist.

I want to test my service with cURL, trying:

curl --data "Line 1\nLine 2\nLine 3" \
-H "Content-Type: text/plain" localhost:3000/parse

This did not work. Nor did some alternatives. And I really didn’t want to have to write the text to a file and load it in.

Turns out there’s a nice little shell trick to let you use escape characters C style, use $'some\ncontent' to use ANSI C escaping. Now you can cURL with newlines!

curl --data $'Line 1\nLine 2\nLine 3' \
-H "Content-Type: text/plain" localhost:3000/parse

Enjoy!

References

GNU Bash ANSI C Quoting
Stack Overflow - Echo Newline Bash Prints \n
Stack Overflow - How to send line break with cURL

CURL on dwmkerr.com

Quick Tip: Sending Newlines with cURL

References