2.9BSD/usr/man/man2/login.2

Compare this file to the similar file:
Show the results in this format:
.TH LOGIN 2
.UC
.SH NAME
login \- flag login process and collect accounting information
.SH SYNOPSIS
.B login(flag, crn);
.br
.B char crn[4];
.SH DESCRIPTION
.I Login
marks the current process as being a login process
and associates the specified
.I crn
with it for accounting purposes.
The
.I crn
is inherited by children, the flag
is not.
.I Crn
is the customer recharge number, also
known as ``job number.''
.PP
By convention, the
.I flag
given to a login process is the
value returned by
.IR ttyslot (3)
for its control typewriter.
This is vestigal.
.PP
Use of this call is restricted
to the super-user.
.SH RETURN VALUE
Upon successful completion, a value of 0 is returned.  Otherwise, a
value of \-1 is returned and
.I errno
is set to indicate the error.
.SH ERRORS
.I Login
will fail if:
.TP 20
[EPERM]
The effective user ID is not the super-user.
.SH ASSEMBLER
(local = 58., login = 1.)
.br
.B sys local; 9f
.br
\&. . .
.br
.B \&.data
.br
.B 9: sys login; flag; crn01; crn23