7.2.4 User Information

The facilities in this section provide an interface to the user and group database. They should be used with care since they are not reentrant.

The following functions accept an object representing user information and return a selected component:

Scheme Procedure: passwd:name pw

The name of the userid.

Scheme Procedure: passwd:passwd pw

The encrypted passwd.

Scheme Procedure: passwd:uid pw

The user id number.

Scheme Procedure: passwd:gid pw

The group id number.

Scheme Procedure: passwd:gecos pw

The full name.

Scheme Procedure: passwd:dir pw

The home directory.

Scheme Procedure: passwd:shell pw

The login shell.

Scheme Procedure: getpwuid uid

Look up an integer userid in the user database.

Scheme Procedure: getpwnam name

Look up a user name string in the user database.

Scheme Procedure: setpwent

Initializes a stream used by getpwent to read from the user database. The next use of getpwent will return the first entry. The return value is unspecified.

Scheme Procedure: getpwent

Read the next entry in the user database stream. The return is a passwd user object as above, or #f when no more entries.

Scheme Procedure: endpwent

Closes the stream used by getpwent. The return value is unspecified.

Scheme Procedure: setpw [arg]

C Function: scm_setpwent (arg)

If called with a true argument, initialize or reset the password data stream. Otherwise, close the stream. The setpwent and endpwent procedures are implemented on top of this.

Scheme Procedure: getpw [user]

C Function: scm_getpwuid (user)

Look up an entry in the user database. user can be an integer, a string, or omitted, giving the behaviour of getpwuid, getpwnam or getpwent respectively.

The following functions accept an object representing group information and return a selected component:

Scheme Procedure: group:name gr

The group name.

Scheme Procedure: group:passwd gr

The encrypted group password.

Scheme Procedure: group:gid gr

The group id number.

Scheme Procedure: group:mem gr

A list of userids which have this group as a supplementary group.

Scheme Procedure: getgrgid gid

Look up an integer group id in the group database.

Scheme Procedure: getgrnam name

Look up a group name in the group database.

Scheme Procedure: setgrent

Initializes a stream used by getgrent to read from the group database. The next use of getgrent will return the first entry. The return value is unspecified.

Scheme Procedure: getgrent

Return the next entry in the group database, using the stream set by setgrent.

Scheme Procedure: endgrent

Closes the stream used by getgrent. The return value is unspecified.

Scheme Procedure: setgr [arg]

C Function: scm_setgrent (arg)

If called with a true argument, initialize or reset the group data stream. Otherwise, close the stream. The setgrent and endgrent procedures are implemented on top of this.

Scheme Procedure: getgr [group]

C Function: scm_getgrgid (group)

Look up an entry in the group database. group can be an integer, a string, or omitted, giving the behaviour of getgrgid, getgrnam or getgrent respectively.

In addition to the accessor procedures for the user database, the following shortcut procedure is also available.

Scheme Procedure: getlogin

C Function: scm_getlogin ()

Return a string containing the name of the user logged in on the controlling terminal of the process, or #f if this information cannot be obtained.