In “The UNIX Programming Environment” from 1984, mail is described like this:
“Sending mail to someone is straightforward. Suppose it is to go to the person with the login name nico.
$ mail nico
Now type in the text of the letter
on as many lines as you like…
After the last line of the letter
type a control-d.
ctl-d
$”
This is also why SMTP is such a fucked up protocol. It was designed so that you could just follow the email protocol by hand. HTTP as well followed this philosophy (up to 2.0 at least). A decade or so ago there was a bug in outlook where you couldn’t have a line with only a period in it because that’s the end-of-email signal in SMTP.
In “The UNIX Programming Environment” from 1984, mail is described like this:
“Sending mail to someone is straightforward. Suppose it is to go to the person with the login name nico.
$ mail nico
Now type in the text of the letter
on as many lines as you like…
After the last line of the letter
type a control-d.
ctl-d
$”
This is also why SMTP is such a fucked up protocol. It was designed so that you could just follow the email protocol by hand. HTTP as well followed this philosophy (up to 2.0 at least). A decade or so ago there was a bug in outlook where you couldn’t have a line with only a period in it because that’s the end-of-email signal in SMTP.