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GETPWENT(3)                Library Functions Manual                GETPWENT(3)



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

SYNOPSIS
       #include <&lt;pwd.h>&gt;

       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) 1991-2014 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.  */
              };


              #if defined __USE_SVID || defined __USE_GNU
              # define __need_FILE
              # include <stdio.h>
              #endif


              #if defined __USE_SVID || 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_SVID
              /* 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);

              /* 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);

              #if defined __USE_POSIX || defined __USE_MISC

              # 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.  */

              # if defined __USE_SVID || defined __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);
              # endif

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

              extern int getpwnam_r (const char *__restrict __name,
                               struct passwd *__restrict __resultbuf,
                               char *__restrict __buffer, size_t __buflen,
                               struct passwd **__restrict __result);


              # ifdef   __USE_SVID
              /* 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);
              # 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)