curl: read headers from file

Question

After the --dump-header writes a file, how to do read those headers back into the next request? I would like to read them from a file because there are a number of them. <

Answer 1

since curl 7.55.0

Easy:

$ curl -H @header_file $URL

... where the header file is a plain text file with a HTTP header on each line. Like this:

Color: red
Shoesize: 11
Secret: yes
User-Agent: foobar/3000
Name: "Joe Smith"

before curl 7.55.0

curl had no way to "bulk change" headers like that, not even from a file.

Your best approach with an old curl version is probably to instead write a shell script that gathers all the headers from the file and use them, like:

#!/bin/sh
while read line; do
  args="$args -H '$line'";
done
curl $args $URL

Invoke the script like this:

$ sh script.sh < header_file