GETPWENT(3)						     Library Functions Manual						       GETPWENT(3)

NAME

       getpwent, getpwuid, getpwnam, setpwent, endpwent - get password file entry

SYNOPSIS

       #include <pwd.h>

       struct passwd *getpwent();

       struct passwd *getpwuid(uid) int uid;

       struct passwd *getpwnam(name) char *name;

       int setpwent();

       int endpwent();

DESCRIPTION

       Getpwent,  getpwuid and getpwnam each return a pointer to an object with the following structure containing the broken-out fields of a line
       in the password file.

	      /* Copyright (C) 1991-2018 Free Software Foundation, Inc.
		 This file is part of the GNU C Library.

		 The GNU C Library is free software; you can redistribute it and/or
		 modify it under the terms of the GNU Lesser General Public
		 License as published by the Free Software Foundation; either
		 version 2.1 of the License, or (at your option) any later version.

		 The GNU C Library is distributed in the hope that it will be useful,
		 but WITHOUT ANY WARRANTY; without even the implied warranty of
		 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
		 Lesser General Public License for more details.

		 You should have received a copy of the GNU Lesser General Public
		 License along with the GNU C Library; if not, see
		 <http://www.gnu.org/licenses/>.  */

	      /*
	       *   POSIX Standard: 9.2.2 User Database Access	<pwd.h>
	       */

	      #ifndef	_PWD_H
	      #define	_PWD_H	  1

	      #include <features.h>

	      __BEGIN_DECLS

	      #include <bits/types.h>

	      #define __need_size_t
	      #include <stddef.h>

	      #if defined __USE_XOPEN || defined __USE_XOPEN2K
	      /* The Single Unix specification says that some more types are
		 available here.  */
	      # ifndef __gid_t_defined
	      typedef __gid_t gid_t;
	      #  define __gid_t_defined
	      # endif

	      # ifndef __uid_t_defined
	      typedef __uid_t uid_t;
	      #  define __uid_t_defined
	      # endif
	      #endif

	      /* The passwd structure.	*/
	      struct passwd
	      {
		char *pw_name;	       /* Username.  */
		char *pw_passwd;       /* Password.  */
		__uid_t pw_uid;        /* User ID.  */
		__gid_t pw_gid;        /* Group ID.  */
		char *pw_gecos;        /* Real name.  */
		char *pw_dir;		    /* Home directory.	*/
		char *pw_shell;        /* Shell program.  */
	      };

	      #ifdef __USE_MISC
	      # include <bits/types/FILE.h>
	      #endif

	      #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
	      /* Rewind the password-file stream.

		 This function is a possible cancellation point and therefore not
		 marked with __THROW.  */
	      extern void setpwent (void);

	      /* Close the password-file stream.

		 This function is a possible cancellation point and therefore not
		 marked with __THROW.  */
	      extern void endpwent (void);

	      /* Read an entry from the password-file stream, opening it if necessary.

		 This function is a possible cancellation point and therefore not
		 marked with __THROW.  */
	      extern struct passwd *getpwent (void);
	      #endif

	      #ifdef	__USE_MISC
	      /* Read an entry from STREAM.

		 This function is not part of POSIX and therefore no official
		 cancellation point.  But due to similarity with an POSIX interface
		 or due to the implementation it is a cancellation point and
		 therefore not marked with __THROW.  */
	      extern struct passwd *fgetpwent (FILE *__stream) __nonnull ((1));

	      /* Write the given entry onto the given stream.

		 This function is not part of POSIX and therefore no official
		 cancellation point.  But due to similarity with an POSIX interface
		 or due to the implementation it is a cancellation point and
		 therefore not marked with __THROW.  */
	      extern int putpwent (const struct passwd *__restrict __p,
			     FILE *__restrict __f);
	      #endif

	      /* Search for an entry with a matching user ID.

		 This function is a possible cancellation point and therefore not
		 marked with __THROW.  */
	      extern struct passwd *getpwuid (__uid_t __uid);

	      /* Search for an entry with a matching username.

		 This function is a possible cancellation point and therefore not
		 marked with __THROW.  */
	      extern struct passwd *getpwnam (const char *__name) __nonnull ((1));

	      #ifdef __USE_POSIX

	      # ifdef __USE_MISC
	      /* Reasonable value for the buffer sized used in the reentrant
		 functions below.  But better use `sysconf'.  */
	      #  define NSS_BUFLEN_PASSWD   1024
	      # endif

	      /* Reentrant versions of some of the functions above.

		 PLEASE NOTE: the `getpwent_r' function is not (yet) standardized.
		 The interface may change in later versions of this library.  But
		 the interface is designed following the principals used for the
		 other reentrant functions so the chances are good this is what the
		 POSIX people would choose.  */

	      # ifdef __USE_MISC
	      /* This function is not part of POSIX and therefore no official
		 cancellation point.  But due to similarity with an POSIX interface
		 or due to the implementation it is a cancellation point and
		 therefore not marked with __THROW.  */
	      extern int getpwent_r (struct passwd *__restrict __resultbuf,
			       char *__restrict __buffer, size_t __buflen,
			       struct passwd **__restrict __result)
			       __nonnull ((1, 2, 4));
	      # endif

	      extern int getpwuid_r (__uid_t __uid,
			       struct passwd *__restrict __resultbuf,
			       char *__restrict __buffer, size_t __buflen,
			       struct passwd **__restrict __result)
			       __nonnull ((2, 3, 5));

	      extern int getpwnam_r (const char *__restrict __name,
			       struct passwd *__restrict __resultbuf,
			       char *__restrict __buffer, size_t __buflen,
			       struct passwd **__restrict __result)
			       __nonnull ((1, 2, 3, 5));

	      # ifdef	__USE_MISC
	      /* Read an entry from STREAM.  This function is not standardized and
		 probably never will.

		 This function is not part of POSIX and therefore no official
		 cancellation point.  But due to similarity with an POSIX interface
		 or due to the implementation it is a cancellation point and
		 therefore not marked with __THROW.  */
	      extern int fgetpwent_r (FILE *__restrict __stream,
			     struct passwd *__restrict __resultbuf,
			     char *__restrict __buffer, size_t __buflen,
			     struct passwd **__restrict __result)
			     __nonnull ((1, 2, 3, 5));
	      # endif

	      #endif	/* POSIX or reentrant */

	      #ifdef __USE_GNU
	      /* Re-construct the password-file line for the given uid
		 in the given buffer.  This knows the format that the caller
		 will expect, but this need not be the format of the password file.

		 This function is not part of POSIX and therefore no official
		 cancellation point.  But due to similarity with an POSIX interface
		 or due to the implementation it is a cancellation point and
		 therefore not marked with __THROW.  */
	      extern int getpw (__uid_t __uid, char *__buffer);
	      #endif

	      __END_DECLS

	      #endif /* pwd.h  */

       The fields pw_quota and pw_comment are unused; the others have meanings described in passwd(5).

       Getpwent reads the next line (opening the file if necessary); setpwent rewinds the file; endpwent closes it.

       Getpwuid and getpwnam search from the beginning until a matching uid or name is found (or until EOF is encountered).

FILES

       /etc/passwd

SEE ALSO

       getlogin(3), getgrent(3), passwd(5)

DIAGNOSTICS

       Null pointer (0) returned on EOF or error.

BUGS

       All information is contained in a static area so it must be copied if it is to be saved.

																       GETPWENT(3)