Name
getpwent, setpwent, endpwent — get password file entry
Synopsis
#include <sys/types.h> #include <pwd.h>
struct passwd
*getpwent( |
void); |
void
setpwent( |
void); |
void
endpwent( |
void); |
![[Note]](../stylesheet/note.png) |
Note | ||||
|---|---|---|---|---|---|
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DESCRIPTION
The getpwent() function
returns a pointer to a structure containing the broken-out
fields of a record from the password database (e.g., the
local password file /etc/passwd, NIS, and LDAP). The first time
getpwent() is called, it
returns the first entry; thereafter, it returns successive
entries.
The setpwent() function
rewinds to the beginning of the password database.
The endpwent() function is
used to close the password database after all processing has
been performed.
The passwd structure is
defined in <pwd.h> as
follows:
struct passwd { char * pw_name;char * pw_passwd;uid_t pw_uid;gid_t pw_gid;char * pw_gecos;char * pw_dir;char * pw_shell;};
For more information about the fields of this structure, see passwd(5).
RETURN VALUE
The getpwent() function
returns a pointer to a passwd
structure, or NULL if there are no more entries or an error
occurred. If an error occurs, errno is set appropriately. If one wants to
check errno after the call, it
should be set to zero before the call.
The return value may point to a static area, and may be
overwritten by subsequent calls to getpwent(), getpwnam(3), or getpwuid(3). (Do not pass
the returned pointer to free(3).)
ERRORS
- EINTR
-
A signal was caught; see signal(7).
- EIO
-
I/O error.
- EMFILE
-
The per-process limit on the number of open file descriptors has been reached.
- ENFILE
-
The system-wide limit on the total number of open files has been reached.
- ENOMEM
-
Insufficient memory to allocate passwd structure.
- ERANGE
-
Insufficient buffer space supplied.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
getpwent() |
Thread safety |
MT-Unsafe race:pwent race:pwentbuf locale |
|
|
Thread safety | MT-Unsafe race:pwent locale |
In the above table, pwent in
race:pwent
signifies that if any of the functions setpwent(), getpwent(), or endpwent() are used in parallel in
different threads of a program, then data races could
occur.
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. The pw_gecos field is not specified
in POSIX, but is present on most implementations.
COLOPHON
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified Sat Jul 24 19:22:14 1993 by Rik Faith (faithcs.unc.edu) Modified Mon May 27 21:37:47 1996 by Martin Schulze (joeylinux.de) |