Curl - Exclamation mark in User Auth/Password
not that complicated, just use "". at least it works on Linux.
for example:
curl -u "username:passwdwithspecialchar" GET https://....
curl -u UserName\\WithSlash:PasswordWithExclamation\! http://....
works fine.
it sends
GET / HTTP/1.1
Authorization: Basic VXNlck5hbWVcV2l0aFNsYXNoOlBhc3N3b3JkV2l0aEV4Y2xhbWF0aW9uIQ==
User-Agent: curl/7.21.0
Host: teststuff1.com:80
Accept: */*
which is "UserName\WithSlash:PasswordWithExclamation!" in the auth string.