Plan 9 /sys/man/6/users

NAME

users – file server user list format

DESCRIPTION

The permanent file servers each maintain a private list of users and groups, in /adm/users by convention. Each line in the file has the format

id:name:leader:members

where name and leader are printable strings excluding the characters ?, =, +, –, /, and :, and members is a comma–separated list of such strings. Such a line defines a user and a group with the given name; the group has a group leader given by leader and group members given by the user names in members. The leader field may be empty, in which case any group member is a group leader. The members field may be empty.
Lines beginning with # are ignored.
The id in a line is an identifier used in the on–disk structures maintained by a file server; there should be no duplicate ids in the file. In fossil(4), ids are arbitrary text strings, typically the same as name. In older Plan 9 file servers, ids are small decimal numbers. In those, a negative id is special: a user with a negative id cannot attach to the file server. The file /adm/users itself is owned by user adm and write protected to others, so it can only be changed via console commands.