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.\"     @(#)acct.2	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt ACCT 2
.Os
.Sh NAME
.Nm acct
.Nd enable or disable process accounting
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn acct "const char *file"
.Sh DESCRIPTION
The
.Fn acct
call enables or disables the collection of system accounting records.
If
.Fa file
is
.Dv NULL ,
accounting is disabled.
If
.Fa file
is an existing, NUL-terminated, pathname, record collection is enabled,
and for every process initiated which terminates under normal
conditions an accounting record is appended to
.Fa file .
Abnormal conditions of termination are reboots or other fatal system problems.
Records for processes which never terminate can not be
produced by
.Fn acct .
.Pp
For more information on the record structure used by
.Fn acct ,
see
.Pa /usr/include/sys/acct.h
and
.Xr acct 5 .
.Pp
This call is permitted only to the super-user.
.Sh NOTES
Accounting is automatically disabled when the file system the
accounting file resides on runs out of space; it is enabled when
space once again becomes available.
For this purpose,
.Fn acct
creates a kernel thread called
.Dq acctwatch .
.Sh RETURN VALUES
On success, zero is returned.
Otherwise, \-1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn acct
will fail if one of the following is true:
.Bl -tag -width Er
.It Bq Er EACCES
Search permission is denied for a component of the path prefix,
or the path name is not a regular file.
.It Bq Er EFAULT
.Fa file
points outside the process's allocated address space.
.It Bq Er EIO
An I/O error occurred while reading from or writing to the file system.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
.It Bq Er ENAMETOOLONG
A component of a pathname exceeded
.Brq Dv NAME_MAX
characters, or an entire path name exceeded
.Brq Dv PATH_MAX
characters.
.It Bq Er ENOENT
The named file does not exist.
.It Bq Er ENOTDIR
A component of the path prefix is not a directory.
.It Bq Er EPERM
The caller is not the super-user.
.It Bq Er EROFS
The named file resides on a read-only file system.
.El
.Pp
Also,
.Fn acct
fails if failed to create kernel thread described above.
See
.Xr fork 2
for
.Va errno
value.
.Sh SEE ALSO
.Xr fork 2 ,
.Xr acct 5 ,
.Xr sa 8
.Sh HISTORY
An
.Fn acct
function call appeared in
.At v7 .