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GETPWENT(3)            FreeBSD Library Functions Manual            GETPWENT(3)

NAME
     getpwent, getpwnam, getpwuid, setpassent, setpwent, endpwent - password
     database operations

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/types.h>
     #include <pwd.h>

     struct passwd *
     getpwent(void);

     struct passwd *
     getpwnam(const char *login);

     struct passwd *
     getpwuid(uid_t uid);

     int
     setpassent(int  stayopen);

     void
     setpwent(void);

     void
     endpwent(void);

DESCRIPTION
     These functions operate on the password database file which is described
     in passwd(5).  Each entry in the database is defined by the structure
     passwd found in the include file <pwd.h>:

           struct passwd {
                   char    *pw_name;       /* user name */
                   char    *pw_passwd;     /* encrypted password */
                   uid_t   pw_uid;         /* user uid */
                   gid_t   pw_gid;         /* user gid */
                   time_t  pw_change;      /* password change time */
                   char    *pw_class;      /* user access class */
                   char    *pw_gecos;      /* Honeywell login info */
                   char    *pw_dir;        /* home directory */
                   char    *pw_shell;      /* default shell */
                   time_t  pw_expire;      /* account expiration */
                   int     pw_fields;      /* internal: fields filled in */
           };

     The functions getpwnam() and getpwuid() search the password database for
     the given login name or user uid, respectively, always returning the
     first one encountered.

     The getpwent() function sequentially reads the password database and is
     intended for programs that wish to process the complete list of users.

     The setpassent() function accomplishes two purposes.  First, it causes
     getpwent() to ``rewind'' to the beginning of the database.  Additionally,
     if stayopen is non-zero, file descriptors are left open, significantly
     speeding up subsequent accesses for all of the routines.  (This latter
     functionality is unnecessary for getpwent() as it doesn't close its file
     descriptors by default.)

     It is dangerous for long-running programs to keep the file descriptors
     open as the database will become out of date if it is updated while the
     program is running.

     The setpwent() function is identical to setpassent() with an argument of
     zero.

     The endpwent() function closes any open files.

     These routines have been written to ``shadow'' the password file, e.g.
     allow only certain programs to have access to the encrypted password.  If
     the process which calls them has an effective uid of 0, the encrypted
     password will be returned, otherwise, the password field of the returned
     structure will point to the string `*'.

YP/NIS INTERACTION
     When the yp(8) password database is enabled, the getpwnam() and
     getpwuid() functions use the YP maps ``passwd.byname'' and
     ``passwd.byuid'', respectively, if the requested password entry is not
     found in the local database.  The getpwent() function will step through
     the YP map ``passwd.byname'' if the entire map is enabled as described in
     passwd(5).

RETURN VALUES
     The functions getpwent(), getpwnam(), and getpwuid(), return a valid
     pointer to a passwd structure on success and a null pointer if end-of-
     file is reached or an error occurs.  The setpassent() function returns 0
     on failure and 1 on success.  The endpwent() and setpwent() functions
     have no return value.

FILES
     /etc/pwd.db         The insecure password database file
     /etc/spwd.db        The secure password database file
     /etc/master.passwd  The current password file
     /etc/passwd         A Version 7 format password file

SEE ALSO
     getlogin(2), getgrent(3), passwd(5), pwd_mkdb(8), vipw(8), yp(8)

HISTORY
     The getpwent(), getpwnam(), getpwuid(), setpwent(), and endpwent()
     functions appeared in Version 7 AT&T UNIX.  The setpassent() function
     appeared in 4.3BSD-Reno.

COMPATIBILITY
     The historic function setpwfile(3), which allowed the specification of
     alternate password databases, has been deprecated and is no longer
     available.

BUGS
     The functions getpwent(), getpwnam(), and getpwuid(), leave their results
     in an internal static object and return a pointer to that object.
     Subsequent calls to the same function will modify the same object.

FreeBSD 11.0-PRERELEASE       September 20, 1994       FreeBSD 11.0-PRERELEASE

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | YP/NIS INTERACTION | RETURN VALUES | FILES | SEE ALSO | HISTORY | COMPATIBILITY | BUGS

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