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GETPWENT(3)		 BSD Library Functions Manual		   GETPWENT(3)

     getpwent, getpwent_r, getpwnam, getpwnam_r, getpwuid, getpwuid_r,
     setpassent, setpwent, endpwent -- password	database operations

     Standard C	Library	(libc, -lc)

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

     struct passwd *

     getpwent_r(struct passwd *pwd, char *buffer, size_t bufsize,
	 struct	passwd **result);

     struct passwd *
     getpwnam(const char *login);

     getpwnam_r(const char *name, struct passwd	*pwd, char *buffer,
	 size_t	bufsize, struct	passwd **result);

     struct passwd *
     getpwuid(uid_t uid);

     getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer, size_t bufsize,
	 struct	passwd **result);

     setpassent(int stayopen);



     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 functions getpwent_r(), getpwnam_r(), and getpwuid_r()	are thread-
     safe versions of getpwent(), getpwnam(), and getpwuid(), respectively.
     The caller	must provide storage for the results of	the search in the pwd,
     buffer, bufsize, and result arguments.  When these	functions are success-
     ful, the pwd argument will	be filled-in, and a pointer to that argument
     will be stored in result.	If an entry is not found or an error occurs,
     result will be set	to NULL.

     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

     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	`*'.

     The functions getpwent(), getpwnam(), and getpwuid() return a valid
     pointer to	a passwd structure on success or NULL if the entry is not
     found or if an error occurs.  In the latter case, errno will be set.  The
     functions getpwent_r(), getpwnam_r(), and getpwuid_r() return 0 if	no er-
     ror occurred, or an error number to indicate failure.  It is not an error
     if	a matching entry is not	found.	(Thus, if result is NULL and the re-
     turn value	is 0, no matching entry	exists.)

     The setpassent() function returns 0 on failure and	1 on success.  The
     endpwent()	and setpwent() functions have no return	value.

     These routines may	fail for any of	the errors specified in	open(2),
     dbopen(3),	socket(2), and connect(2), in addition to the following:

     [ERANGE]		The buffer specified by	the buffer and bufsize argu-
			ments was insufficiently sized to store	the result.
			The caller should retry	with a larger buffer.

     /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

     getlogin(2), getgrent(3), nsswitch.conf(5), passwd(5), pwd_mkdb(8),
     vipw(8), yp(8)

     The getpwent(), getpwnam(), getpwuid(), setpwent(), and endpwent()	func-
     tions appeared in Version 7 AT&T UNIX.  The setpassent() function ap-
     peared in 4.3BSD-Reno.  The getpwent_r(), getpwnam_r(), and getpwuid_r()
     functions appeared	in FreeBSD 5.1.

     The getpwent(), getpwnam(), getpwnam_r(), getpwuid(), getpwuid_r(),
     setpwent(), and endpwent()	functions conform to ISO/IEC 9945-1:1996

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

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

     The functions getpwent(), getpwent_r(), endpwent(), setpassent(), and
     setpwent()	are fairly useless in a	networked environment and should be
     avoided, if possible.  The	getpwent() and getpwent_r() functions make no
     attempt to	suppress duplicate information if multiple sources are speci-
     fied in nsswitch.conf(5).

BSD				April 16, 2003				   BSD


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