How to send a header using a HTTP request through a cURL call?

Question

I wish to send a header to my Apache server on a Linux box. How can I achieve this via a cURL call?

Answer 1

man curl:

   -H/--header <header>           (HTTP)  Extra header to use when getting a web page. You may specify           any number of extra headers. Note that if you should  add  a  custom           header that has the same name as one of the internal ones curl would           use, your externally set header will be used instead of the internal           one.  This  allows  you  to make even trickier stuff than curl would           normally do. You should not replace internally set  headers  without           knowing  perfectly well what you're doing. Remove an internal header           by giving a replacement without content on the  right  side  of  the           colon, as in: -H "Host:".            curl  will  make sure that each header you add/replace get sent with           the proper end of line marker, you should thus not  add  that  as  a           part  of the header content: do not add newlines or carriage returns           they will only mess things up for you.            See also the -A/--user-agent and -e/--referer options.            This option can be used multiple times to add/replace/remove  multi-           ple headers. 

Example:

curl --header "X-MyHeader: 123" www.google.com 

You can see the request that curl sent by adding the -v option.