How to HTTP POST Data with curl and Ampersand (&) Escaping

This article introduces how to HTTP POST data using the Linux curl command and how to escape ampersands (&).

For curl form data POST, two options can be used.

f and d. The difference is that f can only send one key, but d can send multiple parameters.

curl https://example.com/ -X POST -f 'html=hogehogehoge' #=> Ok
curl https://example.com/ -X POST -f 'html=hogehogehoge&fuga=fugafuga' #=> Error
curl https://example.com/ -X POST -d 'html=hogehogehoge' #=> Ok
curl https://example.com/ -X POST -d 'html=hogehogehoge&fuga=fugafuga' #=> Ok

Also, if ”&” is included in the data, it will be recognized as a separate key after the &, so escaping is necessary.

curl https://example.com/ -X POST -d 'html=hogehogehoge&fugafugafuga'

You can escape and use curl at the same time by doing this:

curl https://example.com/ -X POST --data-urlencode 'html=hogehogehoge&fugafugafuga'

If you want to specify multiple parameters, specify multiple options.

curl https://example.com/ -X POST --data-urlencode 'html=hogehogehoge&fugafugafuga'  --data-urlencode 'hoge=hoge'

Or use this script. Bash urlencode and urldecode

urlencode 'hogehogehoge&fugafugafuga'
hogehogehoge%26fugafugafuga

curl https://example.com/ -X POST -d 'html=hogehogehoge%26fugafugafuga'